Installation Guide for Red Hat Enterprise Linux

Red Hat Ceph Storage 2

Installing Red Hat Ceph Storage on Red Hat Enterprise Linux

Red Hat Ceph Storage Documentation Team

Abstract

This document provides instructions on installing Red Hat Ceph Storage on Red Hat Enterprise Linux 7 running on AMD64 and Intel 64 architectures.

Chapter 1. What is Red Hat Ceph Storage?

Red Hat Ceph Storage is a scalable, open, software-defined storage platform that combines the most stable version of the Ceph storage system with a Ceph management platform, deployment utilities, and support services.

Red Hat Ceph Storage is designed for cloud infrastructure and web-scale object storage. Red Hat Ceph Storage clusters consist of the following types of nodes:

Red Hat Storage Ansible Administration node

This type of node acts as the traditional Ceph Administration node did for previous versions of Red Hat Ceph Storage. This type of node provides the following functions:

Note

In Red Hat Ceph Storage 1.3.x, the Ceph Administration node hosted the Calamari monitoring and administration server, and the ceph-deploy utility, which has been deprecated in Red Hat Ceph Storage 2. Use Ceph command-line utility or the Ansible automation application utility instead to install a Red Hat Ceph Storage cluster.

Monitor nodes

Each monitor node runs the monitor daemon (ceph-mon), which maintains a master copy of the cluster map. The cluster map includes the cluster topology. A client connecting to the Ceph cluster retrieves the current copy of the cluster map from the monitor which enables the client to read from and write data to the cluster.

Ceph can run with one monitor; however, to ensure high availability in a production cluster, Red Hat recommends to deploy at least three monitor nodes.

OSD nodes

Each Object Storage Device (OSD) node runs the Ceph OSD daemon (ceph-osd), which interacts with logical disks attached to the node. Ceph stores data on these OSD nodes.

Ceph can run with very few OSD nodes, which the default is three, but production clusters realize better performance beginning at modest scales, for example 50 OSDs in a storage cluster. Ideally, a Ceph cluster has multiple OSD nodes, allowing isolated failure domains by creating the CRUSH map.

MDS nodes

Each Metadata Server (MDS) node runs the MDS daemon (ceph-mds), which manages metadata related to files stored on the Ceph File System (CephFS). The MDS daemon also coordinates access to the shared cluster.

MDS and CephFS are Technology Preview features and as such they are not fully supported yet. For information on MDS installation and configuration, see the Ceph File System Guide (Technology Preview).

Object Gateway node

Ceph Object Gateway node runs the Ceph RADOS Gateway daemon (ceph-radosgw), and is an object storage interface built on top of librados to provide applications with a RESTful gateway to Ceph Storage Clusters. The Ceph RADOS Gateway supports two interfaces:

S3

Provides object storage functionality with an interface that is compatible with a large subset of the Amazon S3 RESTful API.

Swift

Provides object storage functionality with an interface that is compatible with a large subset of the OpenStack Swift API.

For details on the Ceph architecture, see the Architecture Guide.

For minimum recommended hardware, see the Hardware Guide.

Chapter 2. Prerequisites

Figure 2.1. Prerequisite Workflow

RHCS2 Installation Workflow Diagram

Before installing Red Hat Ceph Storage, review the following prerequisites first and prepare each Ceph Monitor, OSD, and client nodes accordingly.

Table 2.1. Prerequisites Checks

TaskRequiredSectionRecommendation

Verifying the operating system version

Yes

Section 2.1, “Operating System”

Verify the PID count

Registering Ceph nodes

Yes

Section 2.2, “Registering Red Hat Ceph Storage Nodes to CDN and Attaching Subscriptions”

 

Enabling Ceph software repositories

Yes

Section 2.3, “Enabling the Red Hat Ceph Storage Repositories”

Two installation methods:

Using a RAID controller

No

Section 2.4, “Configuring RAID Controllers”

For OSD nodes only.

Configuring network Interface

Yes

Section 2.5, “Configuring Network”

Using a public network is required. Having a private network for cluster communication is optional, but recommended.

Configuring a firewall

No

Section 2.6, “Configuring Firewall”

 

Configuring the Network Time Protocol

Yes

Note

 

Creating an Ansible user

No

Section 2.8, “Creating an Ansible User with Sudo Access”

Ansible deployment only. Creating the Ansible user is required on all Ceph nodes.

Enabling password-less SSH

No

Section 2.9, “Enabling Password-less SSH (Ansible Deployment Only)”

Ansible deployment only.

2.1. Operating System

Red Hat Ceph Storage 2 and later requires Red Hat Enterprise Linux 7 Server with a homogeneous version, for example, Red Hat Enterprise Linux 7.2 running on AMD64 and Intel 64 architectures for all Ceph nodes.

Important

Red Hat does not support clusters with heterogeneous operating systems and versions.

Return to prerequisite checklist

2.1.1. Adjusting the PID Count

Hosts with high numbers of OSDs, that being more than 12, may spawn a lot of threads, especially during recovery and re-balancing events. The kernel defaults to a relatively small maximum number of threads, typically 32768.

  1. Check the current pid_max settings:

    # cat /proc/sys/kernel/pid_max
  2. As root, consider setting kernel.pid_max to a higher number of threads. The theoretical maximum is 4,194,303 threads. For example, add the following to the /etc/sysctl.conf file to set it to the maximum value:

    kernel.pid_max = 4194303
  3. As root, to load the changes without a rebooting:

    # sysctl -p
  4. As root, verify the changes:

    # sysctl -a | grep kernel.pid_max

2.2. Registering Red Hat Ceph Storage Nodes to CDN and Attaching Subscriptions

Ceph relies on packages in the Red Hat Enterprise Linux 7 Base content set. Each Ceph node must be able to access the full Red Hat Enterprise Linux 7 Base content.

To do so, register Ceph nodes that can connect to the Internet to the Red Hat Content Delivery Network (CDN) and attach appropriate Ceph subscriptions to the nodes:

Registering Ceph Nodes to CDN

Run all commands in this procedure as root.

  1. Register a node with the Red Hat Subscription Manager. Run the following command and when prompted, enter your Red Hat Customer Portal credentials:

    # subscription-manager register
  2. Pull the latest subscription data from the CDN server:

    # subscription-manager refresh
  3. List all available subscriptions and find the appropriate Red Hat Ceph Storage subscription and determine its Pool ID.

    # subscription-manager list --available
  4. Attach the subscriptions:

    # subscription-manager attach --pool=<pool-id>

    Replace <pool-id> with the Pool ID determined in the previous step.

  5. Enable the Red Hat Enterprise Linux 7 Server Base repository:

    # subscription-manager repos --enable=rhel-7-server-rpms
  6. Enable the Red Hat Enterprise Linux 7 Server Extras repository:

    # subscription-manager repos --enable=rhel-7-server-extras-rpms
  7. Update the node:

    # yum update

Once you register the nodes, enable repositories that provide the Red Hat Ceph Storage packages.

Note

For nodes that cannot access the Internet during the installation, provide the Base content by other means. Either use the Red Hat Satellite server in your environment or mount a local Red Hat Enterprise Linux 7 Server ISO image and point the Ceph cluster nodes to it. For additional details, contact the Red Hat Support.

For more information on registering Ceph nodes with the Red Hat Satellite server, see the How to Register Ceph with Satellite 6 and How to Register Ceph with Satellite 5 articles on the Customer Portal.

Return to prerequisite checklist

2.3. Enabling the Red Hat Ceph Storage Repositories

Before you can install Red Hat Ceph Storage, you must choose an installation method. Red Hat Ceph Storage supports two installation methods:

  • Content Delivery Network (CDN)

    For Ceph Storage clusters with Ceph nodes that can connect directly to the Internet, use Red Hat Subscription Manager to enable the required Ceph repositories on each node.

  • Local Repository

    For Ceph Storage clusters where security measures preclude nodes from accessing the Internet, install Red Hat Ceph Storage 2 from a single software build delivered as an ISO image, which will allow you to install local repositories.

Important

Some Ceph package dependencies require versions that differ from the package versions included in the Extra Packages for Enterprise Linux (EPEL) repository. Disable the EPEL repository to ensure that only the Red Hat Ceph Storage packages are installed.

As root, disable the EPEL repository:

# yum-config-manager --disable epel

This command disables the epel.repo file in /etc/yum.repos.d/.

2.3.1. Content Delivery Network (CDN)

CDN Installations for…​

  • Ansible administration node

    As root, enable the Red Hat Ceph Storage 2 Tools repository:

    # subscription-manager repos --enable=rhel-7-server-rhceph-2-tools-rpms
  • Monitor Nodes

    As root, enable the Red Hat Ceph Storage 2 Monitor repository:

    # subscription-manager repos --enable=rhel-7-server-rhceph-2-mon-rpms
  • OSD Nodes

    As root, enable the Red Hat Ceph Storage 2 OSD repository:

    # subscription-manager repos --enable=rhel-7-server-rhceph-2-osd-rpms
  • RADOS Gateway and Client Nodes

    As root, enable the Red Hat Ceph Storage 2 Tools repository:

    # subscription-manager repos --enable=rhel-7-server-rhceph-2-tools-rpms

Return to prerequisite checklist

2.3.2. Local Repository

For ISO Installations…​

  • Download the Red Hat Ceph Storage ISO

    1. Log in to the Red Hat Customer Portal.
    2. Click Downloads to visit the Software & Download center.
    3. In the Red Hat Ceph Storage area, click Download Software to download the latest version of the software.
    4. Copy the ISO image to the node.
    5. As root, mount the copied ISO image to the /mnt/rhcs2/ directory:

      # mkdir -p /mnt/rhcs2
      # mount -o loop /<path_to_iso>/rhceph-2.0-rhel-7-x86_64.iso /mnt/rhcs2
      Note

      For ISO installations using Ansible to install Red Hat Ceph Storage 2, mounting the ISO and creating a local repository is not required.

  • Create a Local Repository

    1. Copy the ISO image to the node.
    2. Follow the steps in this Knowledgebase solution.
    Note

    If you are completely disconnected from the Internet, then you must use ISO images to receive any updates.

Return to prerequisite checklist

2.4. Configuring RAID Controllers

If a RAID controller with 1-2 GB of cache is installed on a host, enabling write-back caches might result in increased small I/O write throughput. To prevent this problem, the cache must be non-volatile.

Modern RAID controllers usually have super capacitors that provide enough power to drain volatile memory to non-volatile NAND memory during a power loss event. It is important to understand how a particular controller and firmware behave after power is restored.

Some RAID controllers require manual intervention. Hard drives typically advertise to the operating system whether their disk caches should be enabled or disabled by default. However, certain RAID controllers or some firmware do not provide such information, so verify that disk level caches are disabled to avoid file system corruption.

Create a single RAID 0 volume with write-back for each OSD data drive with write-back cache enabled.

If Serial Attached SCSI (SAS) or SATA connected Solid-state Drive (SSD) disks are also present on the controller, investigate whether your controller and firmware support passthrough mode. Passthrough mode helps avoid caching logic, and generally results in much lower latency for fast media.

Return to prerequisite checklist

2.5. Configuring Network

All Ceph clusters require a public network. You must have a network interface card configured to a public network where Ceph clients can reach Ceph monitors and Ceph OSD nodes.

You might have a network interface card for a cluster network so that Ceph can conduct heart-beating, peering, replication, and recovery on a network separate from the public network.

Important

Red Hat does not recommend using a single network interface card for both a public and private network.

Configure the network interfaces and ensure to make the changes persistent so that the settings are identical on reboot. Configure the following settings:

  • The BOOTPROTO parameter is usually set to none for static IP addresses.
  • The ONBOOT parameter must be set to yes. If it is set to no, Ceph might fail to peer on reboot.
  • If you intend to use IPv6 addressing, the IPv6 parameters, for example IPV6INIT must be set to yes except for the IPV6_FAILURE_FATAL parameter. Also, edit the Ceph configuration file to instruct Ceph to use IPv6. Otherwise, Ceph will use IPv4.

Navigate to the /etc/sysconfig/network-scripts/ directory and ensure that the ifcfg-<iface> settings for the public and cluster interfaces are properly configured.

For details on configuring network interface scripts for Red Hat Enterprise Linux 7, see the Configuring a Network Interface Using ifcfg Files chapter in the Networking Guide for Red Hat Enterprise Linux 7.

For additional information on network configuration see the Network Configuration Reference chapter in the Configuration Guide for Red Hat Ceph Storage 2.

Return to prerequisite checklist

2.6. Configuring Firewall

Red Hat Ceph Storage 2 uses the firewalld service, which you must configure to suit your environment.

Monitor nodes use port 6789 for communication within the Ceph cluster. The monitor where the calamari-lite is running uses port 8002 for access to the Calamari REST-based API.

On each Ceph OSD node, the OSD daemon uses several ports in the range 6800-7300:

  • One for communicating with clients and monitors over the public network
  • One for sending data to other OSDs over a cluster network, if available; otherwise, over the public network
  • One for exchanging heartbeat packets over a cluster network, if available; otherwise, over the public network

Ceph object gateway nodes use port 7480 by default. However, you can change the default port, for example to port 80. To use the SSL/TLS service, open port 443.

For more information about public and cluster network, see Network.

Configuring Access

  1. On all Ceph nodes, as root, start the firewalld service, enable it to run on boot, and ensure that it is running:

    # systemctl enable firewalld
    # systemctl start firewalld
    # systemctl status firewalld
  2. As root, on all Ceph Monitor nodes, open port 6789 on the public network:

    # firewall-cmd --zone=public --add-port=6789/tcp
    # firewall-cmd --zone=public --add-port=6789/tcp --permanent

    To limit access based on the source address, run the following commands:

    # firewall-cmd --zone=public --add-rich-rule="rule family="ipv4" \
    source address="<IP-address>/<prefix>" port protocol="tcp" \
    port="6789" accept"
    # firewall-cmd --zone=public --add-rich-rule="rule family="ipv4" \
    source address="<IP-address>/<prefix>" port protocol="tcp" \
    port="6789" accept" --permanent
  3. If calamari-lite is running on the Ceph Monitor node, as root, open port 8002 on the public network:

    # firewall-cmd --zone=public --add-port=8002/tcp
    # firewall-cmd --zone=public --add-port=8002/tcp --permanent

    To limit access based on the source address, run the following commands:

    # firewall-cmd --zone=public --add-rich-rule="rule family="ipv4" \
    source address="<IP-address>/<prefix>" port protocol="tcp" \
    port="8002" accept"
    # firewall-cmd --zone=public --add-rich-rule="rule family="ipv4" \
    source address="<IP-address>/<prefix>" port protocol="tcp" \
    port="8002" accept" --permanent
  4. As root, on all OSD nodes, open ports 6800-7300:

    # firewall-cmd --zone=public --add-port=6800-7300/tcp
    # firewall-cmd --zone=public --add-port=6800-7300/tcp --permanent

    If you have a separate cluster network, repeat the commands with the appropriate zone.

  5. As root, on all object gateway nodes, open the relevant port or ports on the public network.

    1. To open the default port 7480:

      # firewall-cmd --zone=public --add-port=7480/tcp
      # firewall-cmd --zone=public --add-port=7480/tcp --permanent

      To limit access based on the source address, run the following commands:

      # firewall-cmd --zone=public \
      --add-rich-rule="rule family="ipv4" \
      source address="<IP-address>/<prefix>" \
      port protocol="tcp" port="7480" accept"
      # firewall-cmd --zone=public \
      --add-rich-rule="rule family="ipv4" \
      source address="<IP-address>/<prefix>" \
      port protocol="tcp" port="7480" accept" --permanent
    2. Optionally, as root, if you changed the default Ceph object gateway port, for example to port 80, open this port:

      # firewall-cmd --zone=public --add-port=80/tcp
      # firewall-cmd --zone=public --add-port=80/tcp --permanent

      To limit access based on the source address, run the following commands:

      # firewall-cmd --zone=public \
      --add-rich-rule="rule family="ipv4" \
      source address="<IP-address>/<prefix>" \
      port protocol="tcp" port="80" accept"
      # firewall-cmd --zone=public \
      --add-rich-rule="rule family="ipv4" \
      source address="<IP-address>/<prefix>" \
      port protocol="tcp" port="80" accept" --permanent
    3. Optionally, as root, to use SSL/TLS, open port 443:

      # firewall-cmd --zone=public --add-port=443/tcp
      # firewall-cmd --zone=public --add-port=443/tcp --permanent

      To limit access based on the source address, run the following commands:

      # firewall-cmd --zone=public \
      --add-rich-rule="rule family="ipv4" \
      source address="<IP-address>/<prefix>" \
      port protocol="tcp" port="443" accept"
      # firewall-cmd --zone=public \
      --add-rich-rule="rule family="ipv4" \
      source address="<IP-address>/<prefix>" \
      port protocol="tcp" port="443" accept" --permanent

For additional details on firewalld, see the Using Firewalls chapter in the Security Guide for Red Hat Enterprise Linux 7.

Return to prerequisite checklist

2.7. Configuring Network Time Protocol

Note

If using Ansible to deploy a Red Hat Ceph Storage cluster, then the installation, configuration, and enabling NTP is done automatically during the deployment.

You must configure the Network Time Protocol (NTP) on all Ceph Monitor and OSD nodes. Ensure that Ceph nodes are NTP peers. NTP helps preempt issues that arise from clock drift.

  1. As root, install the ntp package:

    # yum install ntp
  2. As root, enable the NTP service to be persistent across a reboot:

    # systemctl enable ntpd
  3. As root, start the NTP service and ensure it is running:

    # systemctl start ntpd
    # systemctl status ntpd
  4. Ensure that NTP is synchronizing Ceph monitor node clocks properly:

    $ ntpq -p

For additional details on NTP for Red Hat Enterprise Linux 7, see the Configuring NTP Using ntpd chapter in the System Administrator’s Guide for Red Hat Enterprise Linux 7.

Return to prerequisite checklist

2.8. Creating an Ansible User with Sudo Access

Ansible must login to Ceph nodes as a user that has passwordless root privileges, because Ansible needs to install software and configuration files without prompting for passwords.

Red Hat recommends creating an Ansible user on all Ceph nodes in the cluster.

Important

Do not use ceph as the user name. The ceph user name is reserved for the Ceph daemons.

A uniform user name across the cluster can improve ease of use, but avoid using obvious user names, because intruders typically use them to for brute force attacks. For example, root, admin, or <productname> are not advised.

The following procedure, substituting <username> for the user name you define, describes how to create an Ansible user with passwordless root privileges on a Ceph node.

  1. Use the ssh command to log in to a Ceph node:

    $ ssh <user_name>@<hostname>

    Replace <hostname> with the host name of the Ceph node.

  2. Create a new Ansible user and set a new password for this user:

    # adduser <username>
    # passwd <username>
  3. Ensure that the user you added has the root privileges:

    # cat << EOF >/etc/sudoers.d/<username>
    <username> ALL = (root) NOPASSWD:ALL
    EOF
  4. Ensure the correct file permissions:

    # chmod 0440 /etc/sudoers.d/<username>

Return to prerequisite checklist

2.9. Enabling Password-less SSH (Ansible Deployment Only)

Since Ansible will not prompt for a password, you must generate SSH keys on the administration node and distribute the public key to each Ceph node.

  1. Generate the SSH keys, but do not use sudo or the root user. Instead, use the Ansible user you created in Creating an Ansible User with Sudo Access. Leave the passphrase empty:

    $ ssh-keygen
    
    Generating public/private key pair.
    Enter file in which to save the key (/ceph-admin/.ssh/id_rsa):
    Enter passphrase (empty for no passphrase):
    Enter same passphrase again:
    Your identification has been saved in /ceph-admin/.ssh/id_rsa.
    Your public key has been saved in /ceph-admin/.ssh/id_rsa.pub.
  2. Copy the key to each Ceph Node, replacing <username> with the user name you created in Creating an Ansible User with Sudo Access and <hostname> with a host name of a Ceph node:

    $ ssh-copy-id <username>@<hostname>
  3. Modify or create (using a utility such as vi) the ~/.ssh/config file of the Ansible administration node so that Ansible can log in to Ceph nodes as the user you created without requiring you to specify the -u <username> option each time you execute the ansible-playbook command. Replace <username> with the name of the user you created and <hostname> with a host name of a Ceph node:

    Host node1
       Hostname <hostname>
       User <username>
    Host node2
       Hostname <hostname>
       User <username>
    Host node3
       Hostname <hostname>
       User <username>

    After editing the ~/.ssh/config file on the Ansible administration node, ensure the permissions are correct:

    $ chmod 600 ~/.ssh/config

Return to prerequisite checklist

Chapter 3. Storage Cluster Installation

Production Ceph storage clusters start with a minimum of three monitor hosts and three OSD nodes containing multiple OSDs.

ceph storage cluster
You can install a Red Hat Ceph Storage cluster by using:

3.1. Installing Red Hat Ceph Storage using Ansible

You can use the Ansible automation application to deploy Red Hat Ceph Storage. Execute the procedures in Figure 2.1, “Prerequisite Workflow” first.

To add more Monitors or OSDs to an existing storage cluster, see the Red Hat Ceph Storage Administration Guide for details:

3.1.1. Installing ceph-ansible

  1. Install the ceph-ansible package:

    # yum install ceph-ansible
  2. As root, add the Ceph hosts to the /etc/ansible/hosts file. Remember to comment out example hosts.

    If the Ceph hosts have sequential naming, consider using a range:

    1. Add Monitor nodes under the [mons] section:

      [mons]
      <monitor-host-name>
      <monitor-host-name>
      <monitor-host-name>
    2. Add OSD nodes under the [osds] section:

      [osds]
      <osd-host-name[1:10]>

      Optionally, use the devices parameter to specify devices that the OSD nodes will use. Use a comma-separated list to list multiple devices.

      [osds]
      <ceph-host-name> devices="[ '<device_1>', '<device_2>' ]"

      For example:

      [osds]
      ceph-osd-01 devices="[ '/dev/sdb', '/dev/sdc' ]"
      ceph-osd-02 devices="[ '/dev/sdb', '/dev/sdc', '/dev/sdd' ]"

      When specifying no devices, then set the osd_auto_discovery option to true in the osds.yml file. See Section 3.1.4, “Configuring Ceph OSD Settings” for more details.

      Using the devices parameter is useful when OSDs use devices with different names or when one of the devices failed on one of the OSDs. See Section A.1, “Ansible Stops Installation Because It Detects Less Devices Than It Expected” for more details.

  3. As the Ansible user, ensure that Ansible can reach the Ceph hosts:

    $ ansible all -m ping
    Note

    See Section 2.8, “Creating an Ansible User with Sudo Access” for more details on creating an Ansible user.

3.1.2. Configuring Ceph Global Settings

  1. Create a directory under the home directory so Ansible can write the keys:

    # cd ~
    # mkdir ceph-ansible-keys
  2. As root, create a symbolic link to the Ansible group_vars directory in the /etc/ansible/ directory:

    # ln -s /usr/share/ceph-ansible/group_vars /etc/ansible/group_vars
  3. As root, create an all.yml file from the all.yml.sample file and open it for editing:

    # cd /etc/ansible/group_vars
    # cp all.yml.sample all.yml
    # vim all.yml
  4. Uncomment the fetch_directory setting under the GENERAL section. Then, point it to the directory you created in step 1:

    fetch_directory: ~/ceph-ansible-keys
  5. Uncomment the ceph_repository_type setting and set it to either cdn or iso:

    ceph_repository_type: cdn
  6. Uncomment the ceph_rhcs setting and set it to true:

    ceph_rhcs: true
    Important

    Using the ceph_stable and ceph_dev repositories, and installing packages from these repositories are not supported by Red Hat.

  7. Select the installation method. There are two approaches:

    1. If Ceph hosts have connectivity to the Red Hat Content Delivery Network (CDN), uncomment the ceph_rhcs_cdn_install setting and set it to true. This is the most common approach to installing Ceph.

      ceph_rhcs_cdn_install: true
    2. If Ceph nodes cannot connect to the Red Hat Content Delivery Network (CDN), uncomment the ceph_rhcs_iso_install setting and set it to true. This approach is most frequently used in high security environments.

      ceph_rhcs_iso_install: true

      Then, uncomment the ceph_rhcs_iso_path setting and specify the path to the ISO image:

      ceph_rhcs_iso_path: <path>

      Example

      ceph_rhcs_iso_path: /path/to/ISO_file.iso

  8. Set the generate_fsid setting to false:

    generate_fsid: false
    Note

    With generate_fsid set to false, then you must specify a value for the File System Identifier (FSID) manually. For example, using the command-line utility, uuidgen, you can generate a Universally Unique Identifier (UUID). Once you generate a UUID, then uncomment the fsid setting and specify the generated UUID:

    fsid: <generated_uuid>

    With generate_fsid set to true, then the UUID will be automatically generated. This removes the need to specify the UUID in the fsid setting.

  9. To enable authentication, uncomment the cephx setting under the Ceph Configuration section. Red Hat recommends running Ceph with authentication enabled:

    cephx: true
  10. Uncomment the monitor_interface setting and specify the network interface:

    monitor_interface:

    Example

    monitor_interface: eth0

    Note

    The monitor_interface setting will use the IPv4 address. To use an IPv6 address, use the monitor_address setting instead.

  11. If not using IPv6, then skip this step. Uncomment and set the ip_version option:

    ip_version: ipv6
  12. Set journal size:

    journal_size: <size_in_MB>

    If not filled, the default journal size will be 5 GB. See Journal Settings for additional details.

  13. Set the public network. Optionally, set the cluster network, too:

    public_network: <public_network>
    cluster_network: <cluster_network>

    See Section 2.5, “Configuring Network” and Network Configuration Reference for additional details.

  14. If not using IPv6, then skip this step. Uncomment and set the radosgw_civetweb_bind_ip option:

    radosgw_civetweb_bind_ip: "[&#123;&#123; ansible_default_ipv6.address &#125;&#125;]"
    Important

    Currently, there is a rendering bug when displaying content within double curly brackets on the Customer Portal. The Customer Portal team is working diligently to resolve this issue.

    The HTML escape codes being displayed in the above step represent the left ({) and right (}) curly brackets respectively. For example, written in long hand, the radosgw_civetweb_bind_ip option would be the following:

    radosgw_civetweb_bind_ip: “[<left_curly_bracket><left_curly_bracket> ansible_default_ipv6.address <right_curly_bracket><right_curly_bracket>]"

3.1.3. Configuring Monitor Settings

Ansible will create Ceph Monitors without any additional configuration steps. However, you may override default settings for authentication, and for use with OpenStack. By default, the Calamari API is disabled.

To configure monitors, perform the following:

  1. Navigate to the /etc/ansible/group_vars/ directory:

    # cd /etc/ansible/group_vars/
  2. As root, create an mons.yml file from mons.yml.sample file and open it for editing:

    # cp mons.yml.sample mons.yml
    # vim mons.yml
  3. To enable the Calamari API, uncomment the calamari setting and set it to true:

    calamari: true
  4. To configure other settings, uncomment them and set appropriate values.

3.1.4. Configuring Ceph OSD Settings

To configure OSDs:

  1. Navigate to the /etc/ansible/group_vars/ directory:

    # cd /etc/ansible/group_vars/
  2. As root, create a new osds.yml file from the osds.yml.sample file and open it for editing:

    # cp osds.yml.sample osds.yml
    # vim osds.yml
  3. Uncomment and set settings that are relevant for your use case. See Table 3.1, “What settings are needed for my use case?” for details.
  4. Once you are done editing the file, save your changes and close the file.

Table 3.1. What settings are needed for my use case?

I want:Relevant OptionsComments

to have the Ceph journal and OSD data co-located on the same device and to specify OSD disks on my own.

devices

journal_collocation: true

The devices setting accepts a list of devices. Ensure that the specified devices correspond to the storage devices on the OSD nodes.

to have the Ceph journal and OSD data co-located on the same device and ceph-ansible to detect and configure all the available devices.

osd_auto_discovery: true

journal_collocation: true

 

to use one or more dedicated devices to store the Ceph journal.

devices

raw_multi_journal: true

raw_journal_devices

The devices and raw_journal_devices settings except a list of devices. Ensure that the devices specified correspond to the storage devices on the OSD nodes.

to use directories instead of disks.

osd_directory: true

osd_directories

The osd_directories setting accepts a list of directories. IMPORTANT: Red Hat currently does not support this scenario.

to have the Ceph journal and OSD data co-located on the same device and encrypt OSD data.

devices

dmcrypt_journal_collocation: true

The devices setting accepts a list of devices. Ensure that the specified devices correspond to the storage devices on the OSD nodes.

Note that all OSDs will be encrypted. For details, see the Encryption chapter in the Red Hat Ceph Storage 2 Architecture Guide.

to use one or more dedicated devices to store the Ceph journal and encrypt OSD data.

devices

dmcrypt_dedicated_journal: true

raw_journal_devices

The devices and raw_journal_devices settings except a list of devices. Ensure that the devices specified correspond to the storage devices on the OSD nodes.

Note that all OSDs will be encrypted. For details, see the Encryption chapter in the Red Hat Ceph Storage 2 Architecture Guide.

to use the BlueStore back end instead of the FileStore back end.

devices

bluestore: true

The devices setting accepts a list of devices.

For details on BlueStore, see the OSD BlueStore (Technology Preview) chapter in the Administration Guide for Red Hat Ceph Storage.

For additional settings, see the osds.yml.sample file located in /usr/share/ceph-ansible/group_vars/.

Warning

Some OSD options will conflict with each other. Avoid enabling these sets of options together:

  • journal_collocation and raw_multi_journal
  • journal_collocation and osd_directory
  • raw_multi_journal and osd_directory

In addition, specifying one of these options is required.

3.1.5. Overriding Ceph Default Settings

Unless otherwise specified in the Ansible configuration files, Ceph uses its default settings.

Because Ansible manages the Ceph configuration file, edit the /etc/ansible/group_vars/all.yml file to change the Ceph configuration. Use the ceph_conf_overrides setting to override the default Ceph configuration.

Ansible supports the same sections as the Ceph configuration file; [global], [mon], [osd], [mds], [rgw], and so on. You can also override particular instances, such as a particular Ceph Object Gateway instance. For example:

###################
# CONFIG OVERRIDE #
###################

ceph_conf_overrides:
   client.rgw.rgw1:
      log_file: /var/log/ceph/ceph-rgw-rgw1.log
Note

Ansible does not include braces when referring to a particular section of the Ceph configuration file. Sections and settings names are terminated with a colon.

Important

Do not set the cluster network with the cluster_network parameter in the CONFIG OVERRIDE section because this can cause two conflicting cluster networks being set in the Ceph configuration file.

To set the cluster network, use the cluster_network parameter in the CEPH CONFIGURATION section. For details, see Configuring Ceph Global Settings.

3.1.6. Deploying a Ceph Cluster

  1. Navigate to the Ansible configuration directory:

    # cd /usr/share/ceph-ansible
  2. As root, create a site.yml file from the site.yml.sample file:

    # cp site.yml.sample site.yml
  3. As the Ansible user, run the Ansible playbook from within the directory where the playbook exists:

    $ ansible-playbook site.yml [-u <user_name>]

    Once the playbook runs, it creates a running Ceph cluster.

    Note

    During the deployment of a Red Hat Ceph Storage cluster with Ansible, the installation, configuration, and enabling NTP is done automatically on each node in the storage cluster.

  4. As root, on the Ceph Monitor nodes, create a Calamari user:

    Syntax

    # calamari-ctl add_user --password <password> --email <email_address> <user_name>

    Example

    # calamari-ctl add_user --password abc123 --email user1@example.com user1

3.1.7. Taking over an Existing Cluster

You can configure Ansible to use a cluster deployed without Ansible. For example, if you upgraded Red Hat Ceph Storage 1.3 clusters to version 2 manually, configure them to use Ansible by following this procedure:

  1. After manually upgrading from version 1.3 to version 2, install and configure Ansible on the administration node. This is the node where the master Ceph configuration file is maintained. See Section 3.2.1, "Installing Ceph Ansible" for details.
  2. Ensure that the Ansible administration node has passwordless ssh access to all Ceph nodes in the cluster. See Section 2.9, “Enabling Password-less SSH (Ansible Deployment Only)” for more details.
  3. As root, create a symbolic link to the Ansible group_vars directory in the /etc/ansible/ directory:

    # ln -s /usr/share/ceph-ansible/group_vars /etc/ansible/group_vars
  4. As root, create an all.yml file from the all.yml.sample file and open it for editing:

    # cd /etc/ansible/group_vars
    # cp all.yml.sample all.yml
    # vim all.yml
  5. Set the generate_fsid setting to false in group_vars/all.yml.
  6. Get the current cluster fsid by executing ceph fsid.
  7. Set the retrieved fsid in group_vars/all.yml.
  8. Modify the Ansible inventory in /etc/ansible/hosts to include Ceph hosts. Add monitors under a [mons] section, OSDs under an [osds] section and gateways under an [rgws] section to identify their roles to Ansible.
  9. Make sure ceph_conf_overrides is updated with the original ceph.conf options used for [global], [osd], [mon], and [client] sections in the all.yml file.

    Options like osd journal, public_network and cluster_network should not be added in ceph_conf_overrides because they are already part of all.yml. Only the options that are not part of all.yml and are in the original ceph.conf should be added to ceph_conf_overrides.

  10. From the /usr/share/ceph-ansible/ directory run the playbook.

    # cd /usr/share/ceph-ansible/
    # cp infrastructure-playbooks/take-over-existing-cluster.yml .
    $ ansible-playbook take-over-existing-cluster.yml -u <username>

3.1.8. Purging a Ceph Cluster

If you deployed a Ceph cluster using Ansible and you want to purge the cluster, then use the purge-cluster.yml Ansible playbook located in the infrastructure-playbooks directory.

Important

Purging a Ceph cluster will lose data stored on the cluster’s OSDs.

Before purging the Ceph cluster…​

Check the osd_auto_discovery option in the osds.yml file. Having this option set to true will cause the purge to fail. To prevent the failure, do the following steps before running the purge:

  1. Declare the OSD devices in the osds.yml file. See Section 3.1.4, “Configuring Ceph OSD Settings” for more details.
  2. Comment out the osd_auto_discovery option in the osds.yml file.

To purge the Ceph cluster…​

  1. As root, navigate to the /usr/share/ceph-ansible/ directory:

    # cd /usr/share/ceph-ansible
  2. As root, copy the purge-cluster.yml Ansible playbook to the current directory:

    # cp infrastructure-playbooks/purge-cluster.yml .
  3. Run the purge-cluster.yml Ansible playbook:

    $ ansible-playbook purge-cluster.yml

3.2. Installing Red Hat Ceph Storage by using the Command-line Interface

All Ceph clusters require at least one monitor, and at least as many OSDs as copies of an object stored on the cluster. Red Hat recommends using three monitors for production environments and a minimum of three Object Storage Devices (OSD).

Bootstrapping the initial monitor is the first step in deploying a Ceph storage cluster. Ceph monitor deployment also sets important criteria for the entire cluster, such as:

  • The number of replicas for pools
  • The number of placement groups per OSD
  • The heartbeat intervals
  • Any authentication requirement

Most of these values are set by default, so it is useful to know about them when setting up the cluster for production.

Installing a Ceph storage cluster by using the command line interface involves these steps:

Important

Red Hat does not support or test upgrading manually deployed clusters. Currently, the only supported way to upgrade to a minor version of Red Hat Ceph Storage 2 is to use the Ansible automation application as described in Important. Therefore, Red Hat recommends to use Ansible to deploy a new cluster with Red Hat Ceph Storage 2. See Section 3.1, “Installing Red Hat Ceph Storage using Ansible” for details.

You can use command-line utilities, such as Yum, to upgrade manually deployed clusters, but Red Hat does not support or test this.

3.2.1. Monitor Bootstrapping

Bootstrapping a Monitor and by extension a Ceph storage cluster, requires the following data:

Unique Identifier
The File System Identifier (fsid) is a unique identifier for the cluster. The fsid was originally used when the Ceph storage cluster was principally used for the Ceph file system. Ceph now supports native interfaces, block devices, and object storage gateway interfaces too, so fsid is a bit of a misnomer.
Cluster Name

Ceph clusters have a cluster name, which is a simple string without spaces. The default cluster name is ceph, but you can specify a different cluster name. Overriding the default cluster name is especially useful when you work with multiple clusters.

When you run multiple clusters in a multi-site architecture, the cluster name for example, us-west, us-east identifies the cluster for the current command-line session.

Note

To identify the cluster name on the command-line interface, specify the Ceph configuration file with the cluster name, for example, ceph.conf, us-west.conf, us-east.conf, and so on.

Example:

# ceph --cluster us-west.conf ...

Monitor Name
Each Monitor instance within a cluster has a unique name. In common practice, the Ceph Monitor name is the node name. Red Hat recommend one Ceph Monitor per node, and no co-locating the Ceph OSD daemons with the Ceph Monitor daemon. To retrieve the short node name, use the hostname -s command.
Monitor Map

Bootstrapping the initial Monitor requires you to generate a Monitor map. The Monitor map requires:

  • The File System Identifier (fsid)
  • The cluster name, or the default cluster name of ceph is used
  • At least one host name and its IP address.
Monitor Keyring
Monitors communicate with each other by using a secret key. You must generate a keyring with a Monitor secret key and provide it when bootstrapping the initial Monitor.
Administrator Keyring
To use the ceph command-line interface utilities, create the client.admin user and generate its keyring. Also, you must add the client.admin user to the Monitor keyring.

The foregoing requirements do not imply the creation of a Ceph configuration file. However, as a best practice, Red Hat recommends creating a Ceph configuration file and populating it with the fsid, the mon initial members and the mon host settings at a minimum.

You can get and set all of the Monitor settings at runtime as well. However, the Ceph configuration file might contain only those settings which overrides the default values. When you add settings to a Ceph configuration file, these settings override the default settings. Maintaining those settings in a Ceph configuration file makes it easier to maintain the cluster.

To bootstrap the initial Monitor, perform the following steps:

  1. Enable the Red Hat Ceph Storage 2 Monitor repository. For ISO-based installations, see the ISO installation section.
  2. On your initial Monitor node, install the ceph-mon package as root:

    # yum install ceph-mon
  3. As root, create a Ceph configuration file in the /etc/ceph/ directory. By default, Ceph uses ceph.conf, where ceph reflects the cluster name:

    Syntax

    # touch /etc/ceph/<cluster_name>.conf

    Example

    # touch /etc/ceph/ceph.conf

  4. As root, generate the unique identifier for your cluster and add the unique identifier to the [global] section of the Ceph configuration file:

    Syntax

    # echo "[global]" > /etc/ceph/<cluster_name>.conf
    # echo "fsid = `uuidgen`" >> /etc/ceph/<cluster_name>.conf

    Example

    # echo "[global]" > /etc/ceph/ceph.conf
    # echo "fsid = `uuidgen`" >> /etc/ceph/ceph.conf

  5. View the current Ceph configuration file:

    $ cat /etc/ceph/ceph.conf
    [global]
    fsid = a7f64266-0894-4f1e-a635-d0aeaca0e993
  6. As root, add the initial Monitor to the Ceph configuration file:

    Syntax

    # echo "mon initial members = <monitor_host_name>[,<monitor_host_name>]" >> /etc/ceph/<cluster_name>.conf

    Example

    # echo "mon initial members = node1" >> /etc/ceph/ceph.conf

  7. As root, add the IP address of the initial Monitor to the Ceph configuration file:

    Syntax

    # echo "mon host = <ip-address>[,<ip-address>]" >> /etc/ceph/<cluster_name>.conf

    Example

    # echo "mon host = 192.168.0.120" >> /etc/ceph/ceph.conf

    Note

    To use IPv6 addresses, you must set the ms bind ipv6 option to true. See the Red Hat Ceph Storage Configuration Guide for more details.

  8. As root, create the keyring for the cluster and generate the Monitor secret key:

    Syntax

    # ceph-authtool --create-keyring /tmp/<cluster_name>.mon.keyring --gen-key -n mon. --cap mon '<capabilites>'

    Example

    # ceph-authtool --create-keyring /tmp/ceph.mon.keyring --gen-key -n mon. --cap mon 'allow *'
    creating /tmp/ceph.mon.keyring

  9. As root, generate an administrator keyring, generate a <cluster_name>.client.admin.keyring user and add the user to the keyring:

    Syntax

    # ceph-authtool --create-keyring /etc/ceph/<cluster_name>.client.admin.keyring --gen-key -n client.admin --set-uid=0 --cap mon '<capabilites>' --cap osd '<capabilites>' --cap mds '<capabilites>'

    Example

    # ceph-authtool --create-keyring /etc/ceph/ceph.client.admin.keyring --gen-key -n client.admin --set-uid=0 --cap mon 'allow *' --cap osd 'allow *' --cap mds 'allow'
    creating /etc/ceph/ceph.client.admin.keyring

  10. As root, add the <cluster_name>.client.admin.keyring key to the <cluster_name>.mon.keyring:

    Syntax

    # ceph-authtool /tmp/<cluster_name>.mon.keyring --import-keyring /etc/ceph/<cluster_name>.client.admin.keyring

    Example

    # ceph-authtool /tmp/ceph.mon.keyring --import-keyring /etc/ceph/ceph.client.admin.keyring
    importing contents of /etc/ceph/ceph.client.admin.keyring into /tmp/ceph.mon.keyring

  11. Generate the Monitor map. Specify using the node name, IP address and the fsid, of the initial Monitor and save it as /tmp/monmap:

    Syntax

    $ monmaptool --create --add <monitor_host_name> <ip-address> --fsid <uuid> /tmp/monmap

    Example

    $ monmaptool --create --add node1 192.168.0.120 --fsid a7f64266-0894-4f1e-a635-d0aeaca0e993 /tmp/monmap
    monmaptool: monmap file /tmp/monmap
    monmaptool: set fsid to a7f64266-0894-4f1e-a635-d0aeaca0e993
    monmaptool: writing epoch 0 to /tmp/monmap (1 monitors)

  12. As root on the initial Monitor node, create a default data directory:

    Syntax

    # mkdir /var/lib/ceph/mon/<cluster_name>-<monitor_host_name>

    Example

    # mkdir /var/lib/ceph/mon/ceph-node1

  13. As root, populate the initial Monitor daemon with the Monitor map and keyring:

    Syntax

    # ceph-mon [--cluster <cluster_name>] --mkfs -i <monitor_host_name> --monmap /tmp/monmap --keyring /tmp/<cluster_name>.mon.keyring

    Example

    # ceph-mon --mkfs -i node1 --monmap /tmp/monmap --keyring /tmp/ceph.mon.keyring
    ceph-mon: set fsid to a7f64266-0894-4f1e-a635-d0aeaca0e993
    ceph-mon: created monfs at /var/lib/ceph/mon/ceph-node1 for mon.node1

  14. View the current Ceph configuration file:

    # cat /etc/ceph/ceph.conf
    [global]
    fsid = a7f64266-0894-4f1e-a635-d0aeaca0e993
    mon_initial_members = node1
    mon_host = 192.168.0.120

    For more details on the various Ceph configuration settings, see the Red Hat Ceph Storage Configuration Guide. The following example of a Ceph configuration file lists some of the most common configuration settings:

    Example

    [global]
    fsid = <cluster-id>
    mon initial members = <monitor_host_name>[, <monitor_host_name>]
    mon host = <ip-address>[, <ip-address>]
    public network = <network>[, <network>]
    cluster network = <network>[, <network>]
    auth cluster required = cephx
    auth service required = cephx
    auth client required = cephx
    osd journal size = <n>
    filestore xattr use omap = true
    osd pool default size = <n>  # Write an object n times.
    osd pool default min size = <n> # Allow writing n copy in a degraded state.
    osd pool default pg num = <n>
    osd pool default pgp num = <n>
    osd crush chooseleaf type = <n>

  15. As root, create the done file:

    Syntax

    # touch /var/lib/ceph/mon/<cluster_name>-<monitor_host_name>/done

    Example

    # touch /var/lib/ceph/mon/ceph-node1/done

  16. As root, update the owner and group permissions on the newly created directory and files:

    Syntax

    # chown -R <owner>:<group> <path_to_directory>

    Example

    # chown -R ceph:ceph /var/lib/ceph/mon
    # chown -R ceph:ceph /var/log/ceph
    # chown -R ceph:ceph /var/run/ceph
    # chown ceph:ceph /etc/ceph/ceph.client.admin.keyring
    # chown ceph:ceph /etc/ceph/ceph.conf
    # chown ceph:ceph /etc/ceph/rbdmap

    Note

    If the Ceph Monitor node is co-located with an OpenStack Controller node, then the Glance and Cinder keyring files must be owned by glance and cinder respectively. For example:

    # ls -l /etc/ceph/
    ...
    -rw-------.  1 glance glance      64 <date> ceph.client.glance.keyring
    -rw-------.  1 cinder cinder      64 <date> ceph.client.cinder.keyring
    ...
  17. For storage clusters with custom names, as root, add the the following line:

    Syntax

    # echo "CLUSTER=<custom_cluster_name>" >> /etc/sysconfig/ceph

    Example

    # echo "CLUSTER=test123" >> /etc/sysconfig/ceph

  18. As root, start and enable the ceph-mon process on the initial Monitor node:

    Syntax

    # systemctl enable ceph-mon.target
    # systemctl enable ceph-mon@<monitor_host_name>
    # systemctl start ceph-mon@<monitor_host_name>

    Example

    # systemctl enable ceph-mon.target
    # systemctl enable ceph-mon@node1
    # systemctl start ceph-mon@node1

  19. Verify that Ceph created the default pools:

    $ ceph osd lspools
    0 rbd,
  20. Verify that the Monitor is running. The status output will look similar to the following example. The Monitor is up and running, but the cluster health will be in a HEALTH_ERR state. This error is indicating that placement groups are stuck and inactive. Once OSDs are added to the cluster and active, the placement group health errors will disappear.

    Example

    $ ceph -s
    cluster a7f64266-0894-4f1e-a635-d0aeaca0e993
    health HEALTH_ERR 192 pgs stuck inactive; 192 pgs stuck unclean; no osds
    monmap e1: 1 mons at {node1=192.168.0.120:6789/0}, election epoch 1, quorum 0 node1
    osdmap e1: 0 osds: 0 up, 0 in
    pgmap v2: 192 pgs, 3 pools, 0 bytes data, 0 objects
    0 kB used, 0 kB / 0 kB avail
    192 creating

To add more Red Hat Ceph Storage Monitors to the storage cluster, see the Red Hat Ceph Storage Administration Guide

3.2.2. OSD Bootstrapping

Once you have your initial monitor running, you can start adding the Object Storage Devices (OSDs). Your cluster cannot reach an active + clean state until you have enough OSDs to handle the number of copies of an object.

The default number of copies for an object is three. You will need three OSD nodes at minimum. However, if you only want two copies of an object, therefore only adding two OSD nodes, then update the osd pool default size and osd pool default min size settings in the Ceph configuration file.

For more details, see the OSD Configuration Reference section in the Red Hat Ceph Storage Configuration Guide.

After bootstrapping the initial monitor, the cluster has a default CRUSH map. However, the CRUSH map does not have any Ceph OSD daemons mapped to a Ceph node.

To add an OSD to the cluster and updating the default CRUSH map, execute the following on each OSD node:

  1. Enable the Red Hat Ceph Storage 2 OSD repository. For ISO-based installations, see the ISO installation section.
  2. As root, install the ceph-osd package on the Ceph OSD node:

    # yum install ceph-osd
  3. Copy the Ceph configuration file and administration keyring file from the initial Monitor node to the OSD node:

    Syntax

    # scp <user_name>@<monitor_host_name>:<path_on_remote_system> <path_to_local_file>

    Example

    # scp root@node1:/etc/ceph/ceph.conf /etc/ceph
    # scp root@node1:/etc/ceph/ceph.client.admin.keyring /etc/ceph

  4. Generate the Universally Unique Identifier (UUID) for the OSD:

    $ uuidgen
    b367c360-b364-4b1d-8fc6-09408a9cda7a
  5. As root, create the OSD instance:

    Syntax

    # ceph osd create <uuid> [<osd_id>]

    Example

    # ceph osd create b367c360-b364-4b1d-8fc6-09408a9cda7a
    0

    Note

    This command outputs the OSD number identifier needed for subsequent steps.

  6. As root, create the default directory for the new OSD:

    Syntax

    # mkdir /var/lib/ceph/osd/<cluster_name>-<osd_id>

    Example

    # mkdir /var/lib/ceph/osd/ceph-0

  7. As root, prepare the drive for use as an OSD, and mount it to the directory you just created. Create a partition for the Ceph data and journal. The journal and the data partitions can be located on the same disk. This example is using a 15 GB disk:

    Syntax

    # parted <path_to_disk> mklabel gpt
    # parted <path_to_disk> mkpart primary 1 10000
    # mkfs -t <fstype> <path_to_partition>
    # mount -o noatime <path_to_partition> /var/lib/ceph/osd/<cluster_name>-<osd_id>
    # echo "<path_to_partition>  /var/lib/ceph/osd/<cluster_name>-<osd_id>   xfs defaults,noatime 1 2" >> /etc/fstab

    Example

    # parted /dev/sdb mklabel gpt
    # parted /dev/sdb mkpart primary 1 10000
    # parted /dev/sdb mkpart primary 10001 15000
    # mkfs -t xfs /dev/sdb1
    # mount -o noatime /dev/sdb1 /var/lib/ceph/osd/ceph-0
    # echo "/dev/sdb1 /var/lib/ceph/osd/ceph-0  xfs defaults,noatime 1 2" >> /etc/fstab

  8. As root, initialize the OSD data directory:

    Syntax

    # ceph-osd -i <osd_id> --mkfs --mkkey --osd-uuid <uuid>

    Example

    # ceph-osd -i 0 --mkfs --mkkey --osd-uuid b367c360-b364-4b1d-8fc6-09408a9cda7a
    ... auth: error reading file: /var/lib/ceph/osd/ceph-0/keyring: can't open /var/lib/ceph/osd/ceph-0/keyring: (2) No such file or directory
    ... created new key in keyring /var/lib/ceph/osd/ceph-0/keyring

    Note

    The directory must be empty before you run ceph-osd with the --mkkey option. If you have a custom cluster name, the ceph-osd utility requires the --cluster option.

  9. As root, register the OSD authentication key. If your cluster name differs from ceph, insert your cluster name instead:

    Syntax

    # ceph auth add osd.<osd_id> osd 'allow *' mon 'allow profile osd' -i /var/lib/ceph/osd/<cluster_name>-<osd_id>/keyring

    Example

    # ceph auth add osd.0 osd 'allow *' mon 'allow profile osd' -i /var/lib/ceph/osd/ceph-0/keyring
    added key for osd.0

  10. As root, add the OSD node to the CRUSH map:

    Syntax

    # ceph [--cluster <cluster_name>] osd crush add-bucket <host_name> host

    Example

    # ceph osd crush add-bucket node2 host

  11. As root, place the OSD node under the default CRUSH tree:

    Syntax

    # ceph [--cluster <cluster_name>] osd crush move <host_name> root=default

    Example

    # ceph osd crush move node2 root=default

  12. As root, add the OSD disk to the CRUSH map

    Syntax

    # ceph [--cluster <cluster_name>] osd crush add osd.<osd_id> <weight> [<bucket_type>=<bucket-name> ...]

    Example

    # ceph osd crush add osd.0 1.0 host=node2
    add item id 0 name 'osd.0' weight 1 at location {host=node2} to crush map

    Note

    You can also decompile the CRUSH map, and add the OSD to the device list. Add the OSD node as a bucket, then add the device as an item in the OSD node, assign the OSD a weight, recompile the CRUSH map and set the CRUSH map. For more details, see the Red Hat Ceph Storage Storage Strategies Guide for more details.

  13. As root, update the owner and group permissions on the newly created directory and files:

    Syntax

    # chown -R <owner>:<group> <path_to_directory>

    Example

    # chown -R ceph:ceph /var/lib/ceph/osd
    # chown -R ceph:ceph /var/log/ceph
    # chown -R ceph:ceph /var/run/ceph
    # chown -R ceph:ceph /etc/ceph

  14. For storage clusters with custom names, as root, add the following line to the /etc/sysconfig/ceph file:

    Syntax

    # echo "CLUSTER=<custom_cluster_name>" >> /etc/sysconfig/ceph

    Example

    # echo "CLUSTER=test123" >> /etc/sysconfig/ceph

  15. The OSD node is in your Ceph storage cluster configuration. However, the OSD daemon is down and in. The new OSD must be up before it can begin receiving data. As root, enable and start the OSD process:

    Syntax

    # systemctl enable ceph-osd.target
    # systemctl enable ceph-osd@<osd_id>
    # systemctl start ceph-osd@<osd_id>

    Example

    # systemctl enable ceph-osd.target
    # systemctl enable ceph-osd@0
    # systemctl start ceph-osd@0

    Once you start the OSD daemon, it is up and in.

Now you have the monitors and some OSDs up and running. You can watch the placement groups peer by executing the following command:

$ ceph -w

To view the OSD tree, execute the following command:

$ ceph osd tree

Example

ID  WEIGHT    TYPE NAME        UP/DOWN  REWEIGHT  PRIMARY-AFFINITY
-1       2    root default
-2       2        host node2
 0       1            osd.0         up         1                 1
-3       1        host node3
 1       1            osd.1         up         1                 1

To expand the storage capacity by adding new OSDs to the storage cluster, see the Red Hat Ceph Storage Administration Guide for more details.

3.2.3. Calamari Server Installation

The Calamari server provides a RESTful API for monitoring Ceph storage clusters.

To install calamari-server, perform the following steps on all Monitor nodes.

  1. As root, enable the Red Hat Ceph Storage 2 Monitor repository
  2. As root, install calamari-server:

    # yum install calamari-server
  3. As root, initialize the calamari-server:

    Syntax

    # calamari-ctl clear --yes-i-am-sure
    # calamari-ctl initialize --admin-username <uid> --admin-password <pwd> --admin-email <email>

    Example

    # calamari-ctl clear --yes-i-am-sure
    # calamari-ctl initialize --admin-username admin --admin-password admin --admin-email cephadm@example.com

    Important

    The calamari-ctl clear --yes-i-am-sure command is only necessary for removing the database of old Calamari server installations. Running this command on a new Calamari server results in an error.

    Note

    During initialization, the calamari-server will generate a self-signed certificate and a private key and place them in the /etc/calamari/ssl/certs/ and /etc/calamari/ssl/private directories respectively. Use HTTPS when making requests. Otherwise, user names and passwords are transmitted in clear text.

The calamari-ctl initialize process generates a private key and a self-signed certificate, which means there is no need to purchase a certificate from a Certificate Authority (CA).

To verify access to the HTTPS API through a web browser, go to the following URL. Click through the untrusted certificate warnings, because the auto-generated certificate is self-signed:

https://<calamari_hostname>:8002/api/v2/cluster

To use a key and certificate from a CA:

  1. Purchase a certificate from a CA. During the process, you will generate a private key and a certificate for CA. Or you can also use the self-signed certificate generated by Calamari.
  2. Save the private key associated to the certificate to a path, preferably under /etc/calamari/ssl/private/.
  3. Save the certificate to a path, preferably under /etc/calamari/ssl/certs/.
  4. Open the /etc/calamari/calamari.conf file.
  5. Under the [calamari_web] section, modify ssl_cert and ssl_key to point to the respective certificate and key path, for example:

    [calamari_web]
    ...
    ssl_cert = /etc/calamari/ssl/certs/calamari-lite-bundled.crt
    ssl_key = /etc/calamari/ssl/private/calamari-lite.key
  6. As root, re-initialize Calamari:

    # calamari-ctl initialize

Chapter 4. Client Installation

Red Hat Ceph Storage supports the following types of Ceph clients:

Ceph CLI
The Ceph command-line interface (CLI) enables administrators to execute Ceph administrative commands. See Section 4.2, “Ceph Command-line Interface Installation” for information on installing the Ceph CLI.
Block Device
The Ceph Block Device is a thin-provisioned, resizable block device. See Section 4.3, “Ceph Block Device Installation” for information on installing Ceph Block Devices.
Object Gateway
The Ceph Object Ǵateway provides its own user management and Swift- and S3-compliant APIs. See Section 4.4, “Ceph Object Gateway Installation” for information on installing Ceph Object Gateways.

In addition, the ceph-ansible utility provides the ceph-client role that copies the Ceph configuration file and the administration keyring to nodes. See Section 4.1, “Installing the ceph-client role” for details.

Important

To use Ceph clients, you must have a Ceph cluster storage running, preferably in the active + clean state.

In addition, before installing the Ceph clients, ensure to perform the tasks listed in the Figure 2.1, “Prerequisite Workflow” section.

4.1. Installing the ceph-client role

The ceph-client role copies the Ceph configuration file and administration keyring to a node. In addition, you can use this role to create custom pools and clients.

Perform the following tasks on the Ansible administration node, see Installing ceph-ansible for details.

  1. Add a new section [clients] to the /etc/ansible/hosts file:

    [clients]
    <client-hostname>

    Replace <client-hostname> with the host name of the node where you want to install the ceph-client role.

  2. Navigate to the /etc/ansible/group_vars/ directory:

    $ cd /etc/ansible/group_vars
  3. Create a new copy of the clients.yml.sample file named clients.yml:

    # cp clients.yml.sample clients.yml
  4. Optionally, instruct ceph-client to create pools and clients.

    1. Update clients.yml.

      • Uncomment the user_config setting and set it to true.
      • Uncomment the pools and keys sections and update them as required. You can define custom pools and client names altogether with the cephx capabilities.
    2. Add the osd_pool_default_pg_num setting to the ceph_conf_overrides section in the all.yml file:

      ceph_conf_overrides:
         global:
            osd_pool_default_pg_num: <number>

      Replace <number> with the default number of placement groups.

  5. Run the Ansible playbook:

    $ ansible-playbook site.yml

4.2. Ceph Command-line Interface Installation

The Ceph command-line interface (CLI) is provided by the ceph-common package and includes the following utilities:

  • ceph
  • ceph-authtool
  • ceph-dencoder
  • rados

To install the Ceph CLI:

  1. On the client node, enable the Tools repository.
  2. On the client node, install the ceph-common package:

    # yum install ceph-common
  3. From the initial monitor node, copy the Ceph configuration file, in this case ceph.conf, and the administration keyring to the client node:

    Syntax

    # scp /etc/ceph/<cluster_name>.conf <user_name>@<client_host_name>:/etc/ceph/
    # scp /etc/ceph/<cluster_name>.client.admin.keyring <user_name>@<client_host_name:/etc/ceph/

    Example

    # scp /etc/ceph/ceph.conf root@node1:/etc/ceph/
    # scp /etc/ceph/ceph.client.admin.keyring root@node1:/etc/ceph/

    Replace <client_host_name> with the host name of the client node.

4.3. Ceph Block Device Installation

The following procedure shows how to install and mount a thin-provisioned, resizable Ceph Block Device.

Important

Ceph Block Devices must be deployed on separate nodes from the Ceph Monitor and OSD nodes. Running kernel clients and kernel server daemons on the same node can lead to kernel deadlocks.

Before you start

Installing Ceph Block Devices by Using the Command Line

  1. Create a Ceph Block Device user named client.rbd with full permissions to files on OSD nodes (osd 'allow rwx') and output the result to a keyring file:

    ceph auth get-or-create client.rbd mon 'allow r' osd 'allow rwx pool=<pool_name>' \
    -o /etc/ceph/rbd.keyring

    Replace <pool_name> with the name of the pool that you want to allow client.rbd to have access to, for example rbd:

    # ceph auth get-or-create \
    client.rbd mon 'allow r' osd 'allow rwx pool=rbd' \
    -o /etc/ceph/rbd.keyring

    See the User Management section in the Red Hat Ceph Storage Administration Guide for more information about creating users.

  2. Create a block device image:

    rbd create <image_name> --size <image_size> --pool <pool_name> \
    --name client.rbd --keyring /etc/ceph/rbd.keyring

    Specify <image_name>, <image_size>, and <pool_name>, for example:

    $ rbd create image1 --size 4096 --pool rbd \
    --name client.rbd --keyring /etc/ceph/rbd.keyring
    Warning

    The default Ceph configuration includes the following Ceph Block Device features:

    • layering
    • exclusive-lock
    • object-map
    • deep-flatten
    • fast-diff

    If you use the kernel RBD (krbd) client, you will not be able to map the block device image because the current kernel version included in Red Hat Enterprise Linux 7.3 does not support object-map, deep-flatten, and fast-diff.

    To work around this problem, disable the unsupported features. Use one of the following options to do so:

    • Disable the unsupported features dynamically:

      rbd feature disable <image_name> <feature_name>

      For example:

      # rbd feature disable image1 object-map deep-flatten fast-diff
    • Use the --image-feature layering option with the rbd create command to enable only layering on newly created block device images.
    • Disable the features be default in the Ceph configuration file:

      rbd_default_features = 1

    This is a known issue, for details see the Release Notes Red Hat Ceph Storage 2.2.

    All these features work for users that use the user-space RBD client to access the block device images.

  3. Map the newly created image to the block device:

    rbd map <image_name> --pool <pool_name>\
    --name client.rbd --keyring /etc/ceph/rbd.keyring

    For example:

    # rbd map image1 --pool rbd --name client.rbd \
    --keyring /etc/ceph/rbd.keyring
    Important

    Kernel block devices currently only support the legacy straw bucket algorithm in the CRUSH map. If you have set the CRUSH tunables to optimal, you must set them to legacy or an earlier major release, otherwise, you will not be able to map the image.

    Alternatively, replace straw2 with straw in the CRUSH map. For details, see the Editing a CRUSH Map chapter in the Storage Strategies Guide for Red Hat Ceph Storage 2.

  4. Use the block device by creating a file system:

    mkfs.ext4 -m5 /dev/rbd/<pool_name>/<image_name>

    Specify the pool name and the image name, for example:

    # mkfs.ext4 -m5 /dev/rbd/rbd/image1

    This can take a few moments.

  5. Mount the newly created file system:

    mkdir <mount_directory>
    mount /dev/rbd/<pool_name>/<image_name> <mount_directory>

    For example:

    # mkdir /mnt/ceph-block-device
    # mount /dev/rbd/rbd/image1 /mnt/ceph-block-device

For additional details, see the Red Hat Ceph Storage Block Device Guide.

4.4. Ceph Object Gateway Installation

The Ceph object gateway, also know as the RADOS gateway, is an object storage interface built on top of the librados API to provide applications with a RESTful gateway to Ceph storage clusters.

For more information about the Ceph object gateway, see the Object Gateway Guide for Red Hat Enterprise Linux.

There are two ways to install the Ceph object gateway:

4.4.1. Installing Ceph Object Gateway by using Ansible

Perform the following tasks on the Ansible administration node, see Install Ceph Ansible for details.

  1. As root, create the rgws file from the sample file:

    # cd /etc/ansible/group_vars
    # cp rgws.yml.sample rgws.yml
  2. To copy the administrator key to the Ceph Object Gateway node, uncomment the copy_admin_key setting in the /etc/ansible/group_vars/rgws.yml file:

    copy_admin_key: true
  3. The rgws.yml file may specify a different default port than the default port 7480. For example:

    ceph_rgw_civetweb_port: 80
  4. Generally, to change default settings, uncomment the settings in the rgw.yml file, and make changes accordingly. To make additional changes to settings that aren’t in the rgw.yml file, use ceph_conf_overrides: in the all.yml file. For example, set the rgw_dns_name: with the host of the DNS server and ensure the cluster’s DNS server to configure it for wild cards to enable S3 subdomains.

    ceph_conf_overrides:
       client.rgw.rgw1:
          rgw_dns_name: <host_name>
          rgw_override_bucket_index_max_shards: 16
          rgw_bucket_default_quota_max_objects: 1638400

    For advanced configuration details, refer to the Ceph Object Gateway for Production guide. Advanced topics include:

  5. Add the radosgw_interface setting to the group_vars/all.yml file, and specify the network interface for the Ceph Object Gateway. For example:

    radosgw_interface: eth0
  6. Add gateway hosts to the /etc/ansible/hosts file under the [rgws] section to identify their roles to Ansible. If the hosts have sequential naming, you can use a range. For example:

    [rgws]
    <rgw_host_name_1>
    <rgw_host_name_2>
    <rgw_host_name[3..10]>
  7. Navigate to the Ansible configuration directory, /etc/ansible/:

    $ cd /usr/share/ceph-ansible
  8. Run the Ansible playbook:

    $ ansible-playbook site.yml
Note

Ansible ensures that each Ceph Object Gateway is running.

For a single site configuration, add Ceph Object Gateways to the Ansible configuration.

For multi-site deployments, you should have an Ansible configuration for each zone. That is, Ansible will create a Ceph storage cluster and gateway instances for that zone.

After installation for a multi-site cluster is complete, proceed to the Multi-site chapter in the Object Gateway Guide for Red Hat Enterprise Linux for details on configuring a cluster for multi-site.

4.4.2. Installing Ceph Object Gateway Manually

  1. Enable the Red Hat Ceph Storage 2 Tools repository. For ISO-based installations, see the ISO installation section.
  2. On the Object Gateway node, install the ceph-radosgw package:

    # yum install ceph-radosgw
  3. On the initial Monitor node, do the following steps.

    1. Update the Ceph configuration file as follows:

      [client.rgw.<obj_gw_hostname>]
      host = <obj_gw_hostname>
      rgw frontends = "civetweb port=80"
      rgw dns name = <obj_gw_hostname>.example.com

      Where <obj_gw_hostname> is a short host name of the gateway node. To view the short host name, use the hostname -s command.

    2. Copy the updated configuration file to the new Object Gateway node and all other nodes in the Ceph storage cluster:

      Syntax

      # scp /etc/ceph/<cluster_name>.conf <user_name>@<target_host_name>:/etc/ceph

      Example

      # scp /etc/ceph/ceph.conf root@node1:/etc/ceph/

    3. Copy the <cluster_name>.client.admin.keyring file to the new Object Gateway node:

      Syntax

      # scp /etc/ceph/<cluster_name>.client.admin.keyring <user_name>@<target_host_name>:/etc/ceph/

      Example

      # scp /etc/ceph/ceph.client.admin.keyring root@node1:/etc/ceph/

  4. On the Object Gateway node, create the data directory:

    Syntax

    # mkdir -p /var/lib/ceph/radosgw/<cluster_name>-rgw.`hostname -s`

    Example

    # mkdir -p /var/lib/ceph/radosgw/ceph-rgw.`hostname -s`

  5. On the Object Gateway node, add a user and keyring to bootstrap the object gateway:

    Syntax

    # ceph auth get-or-create client.rgw.`hostname -s` osd 'allow rwx' mon 'allow rw' -o /var/lib/ceph/radosgw/<cluster_name>-rgw.`hostname -s`/keyring

    Example

    # ceph auth get-or-create client.rgw.`hostname -s` osd 'allow rwx' mon 'allow rw' -o /var/lib/ceph/radosgw/ceph-rgw.`hostname -s`/keyring

    Important

    When you provide capabilities to the gateway key you must provide the read capability. However, providing the Monitor write capability is optional; if you provide it, the Ceph Object Gateway will be able to create pools automatically.

    In such a case, ensure to specify a reasonable number of placement groups in a pool. Otherwise, the gateway uses the default number, which might not be suitable for your needs. See Ceph Placement Groups (PGs) per Pool Calculator for details.

  6. On the Object Gateway node, create the done file:

    Syntax

    # touch /var/lib/ceph/radosgw/<cluster_name>-rgw.`hostname -s`/done

    Example

    # touch /var/lib/ceph/radosgw/ceph-rgw.`hostname -s`/done

  7. On the Object Gateway node, change the owner and group permissions:

    # chown -R ceph:ceph /var/lib/ceph/radosgw
    # chown -R ceph:ceph /var/log/ceph
    # chown -R ceph:ceph /var/run/ceph
    # chown -R ceph:ceph /etc/ceph
  8. For storage clusters with custom names, as root, add the the following line:

    Syntax

    # echo "CLUSTER=<custom_cluster_name>" >> /etc/sysconfig/ceph

    Example

    # echo "CLUSTER=test123" >> /etc/sysconfig/ceph

  9. On the Object Gateway node, open TCP port 80:

    # firewall-cmd --zone=public --add-port=80/tcp
    # firewall-cmd --zone=public --add-port=80/tcp --permanent
  10. On the Object Gateway node, start and enable the ceph-radosgw process:

    Syntax

    # systemctl enable ceph-radosgw.target
    # systemctl enable ceph-radosgw@rgw.<rgw_hostname>
    # systemctl start ceph-radosgw@rgw.<rgw_hostname>

    Example

    # systemctl enable ceph-radosgw.target
    # systemctl enable ceph-radosgw@rgw.node1
    # systemctl start ceph-radosgw@rgw.node1

Once installed, the Ceph Object Gateway automatically creates pools if the write capability is set on the Monitor. See the Pools chapter in the Storage Strategies Guide for information on creating pools manually.

Chapter 5. Upgrading Ceph Storage Cluster

There are two main upgrading paths:

  • from Red Hat Ceph Storage 1.3 to 2 (Important)
  • between minor versions of Red Hat Ceph Storage 2 or between asynchronous updates (Important)

5.1. Upgrading from Red Hat Ceph Storage 1.3 to 2

Important

Please contact Red Hat support prior to upgrading, if you have a large Ceph Object Gateway storage cluster with millions of objects present in buckets.

For more details refer to the Red Hat Ceph Storage 2.5 Release Notes, under the Slow OSD startup after upgrading to Red Hat Ceph Storage 2.5 heading.

You can upgrade the Ceph Storage Cluster in a rolling fashion and while the cluster is running. Upgrade each node in the cluster sequentially, only proceeding to the next node after the previous node is done.

Red Hat recommends upgrading the Ceph components in the following order:

  • Monitor nodes
  • OSD nodes
  • Ceph Object Gateway nodes
  • All other Ceph client nodes

Two methods are available to upgrade a Red Hat Ceph Storage 1.3.2 to 2.0:

  • Using Red Hat’s Content Delivery Network (CDN)
  • Using a Red Hat provided ISO image file

After upgrading the storage cluster you might have a health warning regarding the CRUSH map using legacy tunables. See the Red Hat Ceph Storage Strategies Guide for more information.

Example

$ ceph -s
    cluster 848135d7-cdb9-4084-8df2-fb5e41ae60bd
     health HEALTH_WARN
            crush map has legacy tunables (require bobtail, min is firefly)
     monmap e1: 1 mons at {ceph1=192.168.0.121:6789/0}
            election epoch 2, quorum 0 ceph1
     osdmap e83: 2 osds: 2 up, 2 in
      pgmap v1864: 64 pgs, 1 pools, 38192 kB data, 17 objects
            10376 MB used, 10083 MB / 20460 MB avail
                  64 active+clean

Important

Red Hat recommends all Ceph clients to be running the same version as the Ceph storage cluster.

5.1.1. Upgrading a Ceph Monitor Node

Red Hat recommends a minimum of three Monitors for a production storage cluster. There must be an odd number of Monitors. While you are upgrading one Monitor, the storage cluster will still have quorum.

For Red Hat Ceph Storage 1.3.2 Monitor nodes running on Red Hat Enterprise Linux 7, perform the following steps on each Monitor node in the storage cluster. Sequentially upgrading one Monitor node at a time.

  1. As root, disable any Red Hat Ceph Storage 1.3.x repositories:

    # subscription-manager repos --disable=rhel-7-server-rhceph-1.3-mon-rpms --disable=rhel-7-server-rhceph-1.3-installer-rpms --disable=rhel-7-server-rhceph-1.3-calamari-rpms
    Note

    If an ISO-based installation was performed for Red Hat Ceph Storage 1.3.x, then skip this first step.

  2. Enable the Red Hat Ceph Storage 2 Monitor repository. For ISO-based installations, see the ISO installation section.
  3. As root, stop the Monitor process:

    Syntax

    # service ceph stop <daemon_type>.<monitor_host_name>

    Example

    # service ceph stop mon.node1

  4. As root, update the ceph-mon package:

    # yum update ceph-mon
  5. As root, update the owner and group permissions:

    Syntax

    # chown -R <owner>:<group> <path_to_directory>

    Example

    # chown -R ceph:ceph /var/lib/ceph/mon
    # chown -R ceph:ceph /var/log/ceph
    # chown -R ceph:ceph /var/run/ceph
    # chown ceph:ceph /etc/ceph/ceph.client.admin.keyring
    # chown ceph:ceph /etc/ceph/ceph.conf
    # chown ceph:ceph /etc/ceph/rbdmap

    Note

    If the Ceph Monitor node is co-located with an OpenStack Controller node, then the Glance and Cinder keyring files must be owned by glance and cinder respectively. For example:

    # ls -l /etc/ceph/
    ...
    -rw-------.  1 glance glance      64 <date> ceph.client.glance.keyring
    -rw-------.  1 cinder cinder      64 <date> ceph.client.cinder.keyring
    ...
  6. If SELinux is set to enforcing or permissive mode, then set a relabelling of the SELinux context on files for the next reboot:

    # touch /.autorelabel
    Warning

    Relabeling will take a long time to complete, because SELinux must traverse every file system and fix any mislabeled files. To exclude directories from being relabelled, add the directory to the /etc/selinux/fixfiles_exclude_dirs file before rebooting.

Note

In environments with large number of objects per placement group (PG), the directory enumeration speed will decrease, causing a negative impact to performance. This is caused by the addition of xattr queries which verifies the SELinux context. Setting the context at mount time removes the xattr queries for context and helps overall disk performance, especially on slower disks.

Add the following line to the [osd] section in the /etc/ceph/ceph.conf file:

osd_mount_options_xfs=rw,noatime,inode64,context="system_u:object_r:ceph_var_lib_t:s0"
  1. As root, replay device events from the kernel:

    # udevadm trigger
  2. As root, enable the ceph-mon process:

    # systemctl enable ceph-mon.target
    # systemctl enable ceph-mon@<monitor_host_name>
  3. As root, reboot the Monitor node:

    # shutdown -r now
  4. Once the Monitor node is up, check the health of the Ceph storage cluster before moving to the next Monitor node:

    # ceph -s

To add more Red Hat Ceph Storage Monitors to the storage cluster, see the Red Hat Ceph Storage Administration Guide

5.1.2. Upgrading a Ceph OSD Node

Red Hat recommends having a minimum of three OSD nodes in the Ceph storage cluster. For Red Hat Ceph Storage 1.3.2 OSD nodes running on Red Hat Enterprise Linux 7, perform the following steps on each OSD node in the storage cluster. Sequentially upgrading one OSD node at a time.

During the upgrade of an OSD node, some placement groups will become degraded, because the OSD might be down or restarting. You will need to tell the storage cluster not to mark an OSD out, because you do not want to trigger a recovery. The default behavior is to mark an OSD out of the CRUSH map after five minutes.

On a Monitor node, set noout and norebalance flags for the OSDs:

# ceph osd set noout
# ceph osd set norebalance

Perform the following steps on each OSD node in the storage cluster. Sequentially upgrading one OSD node at a time. If an ISO-based installation was performed for Red Hat Ceph Storage 1.3, then skip this first step.

  1. As root, disable the Red Hat Ceph Storage 1.3 repositories:

    # subscription-manager repos --disable=rhel-7-server-rhceph-1.3-osd-rpms --disable=rhel-7-server-rhceph-1.3-installer-rpms --disable=rhel-7-server-rhceph-1.3-calamari-rpms
  2. Enable the Red Hat Ceph Storage 2 OSD repository. For ISO-based installations, see the ISO installation section.
  3. As root, stop any running OSD process:

    Syntax

    # service ceph stop <daemon_type>.<osd_id>

    Example

    # service ceph stop osd.0

  4. As root, update the ceph-osd package:

    # yum update ceph-osd
  5. As root, update the owner and group permissions on the newly created directory and files:

    Syntax

    # chown -R <owner>:<group> <path_to_directory>

    Example

    # chown -R ceph:ceph /var/lib/ceph/osd
    # chown -R ceph:ceph /var/log/ceph
    # chown -R ceph:ceph /var/run/ceph
    # chown -R ceph:ceph /etc/ceph

    Note

    Running the following find command might speed up the process of changing ownership by running the chown command in parallel on a Ceph storage cluster with a large number of disks:

    # find /var/lib/ceph/osd -maxdepth 1 -mindepth 1 -print | xargs -P12 -n1 chown -R ceph:ceph
  6. If SELinux is set to enforcing or permissive mode, then set a relabelling of the SELinux context on files for the next reboot:

    # touch /.autorelabel
    Warning

    Relabeling will take a long time to complete, because SELinux must traverse every file system and fix any mislabeled files. To exclude directories from being relabelled, add the directory to the /etc/selinux/fixfiles_exclude_dirs file before rebooting.

Note

In environments with large number of objects per placement group (PG), the directory enumeration speed will decrease, causing a negative impact to performance. This is caused by the addition of xattr queries which verifies the SELinux context. Setting the context at mount time removes the xattr queries for context and helps overall disk performance, especially on slower disks.

Add the following line to the [osd] section in the /etc/ceph/ceph.conf file:

osd_mount_options_xfs=rw,noatime,inode64,context="system_u:object_r:ceph_var_lib_t:s0"
  1. As root, replay device events from the kernel:

    # udevadm trigger
  2. As root, enable the ceph-osd process:

    # systemctl enable ceph-osd.target
    # systemctl enable ceph-osd@<osd_id>
  3. As root, reboot the OSD node:

    # shutdown -r now
  4. Move to the next OSD node.

    Note

    While the noout and norebalance flags are set, the storage cluster will have the HEALTH_WARN status:

    $ ceph health
    HEALTH_WARN noout,norebalance flag(s) set

Once you are done upgrading the Ceph storage cluster, unset the previously set OSD flags and verify the storage cluster status.

On a Monitor node, and after all OSD nodes have been upgraded, unset the noout and norebalance flags:

# ceph osd unset noout
# ceph osd unset norebalance

In addition, set the require_jewel_osds flag. This flag ensures that no more OSDs with Red Hat Ceph Storage 1.3 can be added to the storage cluster. If you do not set this flag, the storage status will be HEALTH_WARN.

# ceph osd set require_jewel_osds

To expand the storage capacity by adding new OSDs to the storage cluster, see the Red Hat Ceph Storage Administration Guide for more details.

5.1.3. Upgrading the Ceph Object Gateway Nodes

This section describes steps to upgrade a Ceph Object Gateway node to a later version.

Before You Start
  • Red Hat recommends putting a Ceph Object Gateway behind a load balancer, such as HAProxy. If you use a load balancer, remove the Ceph Object Gateway from the load balancer once no requests are being served.
  • If you use a custom name for the region pool, specified in the rgw_region_root_pool parameter, add the rgw_zonegroup_root_pool parameter to the [global] section of the Ceph configuration file. Set the value of rgw_zonegroup_root_pool to be the same as rgw_region_root_pool, for example:

    [global]
    rgw_zonegroup_root_pool = .us.rgw.root
Procedure: Upgrading the Ceph Object Gateway Node
  1. If you used online repositories to install Red Hat Ceph Storage, disable the 1.3 repositories.

    # subscription-manager repos --disable=rhel-7-server-rhceph-1.3-tools-rpms --disable=rhel-7-server-rhceph-1.3-installer-rpms --disable=rhel-7-server-rhceph-1.3-calamari-rpms
  2. Enable the Red Hat Ceph Storage 2 Tools repository. For ISO-based installations, see the ISO Installation section.
  3. Stop the Ceph Object Gateway process (ceph-radosgw):

    # service ceph-radosgw stop
  4. Update the ceph-radosgw package:

    # yum update ceph-radosgw
  5. Change the owner and group permissions on the newly created /var/lib/ceph/radosgw/ and /var/log/ceph/ directories and their content to ceph.

    # chown -R ceph:ceph /var/lib/ceph/radosgw
    # chown -R ceph:ceph /var/log/ceph
  6. If SELinux is set to run in enforcing or permissive mode, instruct it to relabel SELinux context on the next boot.

    # touch /.autorelabel
    Important

    Relabeling takes a long time to complete, because SELinux must traverse every file system and fix any mislabeled files. To exclude directories from being relabeled, add them to the /etc/selinux/fixfiles_exclude_dirs file before rebooting.

Note

In environments with large number of objects per placement group (PG), the directory enumeration speed will decrease, causing a negative impact to performance. This is caused by the addition of xattr queries which verifies the SELinux context. Setting the context at mount time removes the xattr queries for context and helps overall disk performance, especially on slower disks.

Add the following line to the [osd] section in the /etc/ceph/ceph.conf file:

osd_mount_options_xfs=rw,noatime,inode64,context="system_u:object_r:ceph_var_lib_t:s0"
  1. Enable the ceph-radosgw process.

    # systemctl enable ceph-radosgw.target
    # systemctl enable ceph-radosgw@rgw.<hostname>

    Replace <hostname> with the name of the Ceph Object Gateway host, for example gateway-node.

    # systemctl enable ceph-radosgw.target
    # systemctl enable ceph-radosgw@rgw.gateway-node
  2. Reboot the Ceph Object Gateway node.

    # shutdown -r now
  3. If you use a load balancer, add the Ceph Object Gateway node back to the load balancer.
  4. Repeat these steps on a next Ceph Object Gateway node.
See Also

5.1.4. Upgrading a Ceph Client Node

Ceph clients can be the RADOS Gateway, RADOS block devices, the Ceph command-line interface (CLI), Nova compute nodes, qemu-kvm, or any custom application using the Ceph client-side libraries. Red Hat recommends all Ceph clients to be running the same version as the Ceph storage cluster.

Important

Red Hat recommends stopping all IO running against a Ceph client node while the packages are being upgraded. Not stopping all IO might cause unexpected errors to occur.

  1. As root, disable any Red Hat Ceph Storage 1.3 repositories:

    # subscription-manager repos --disable=rhel-7-server-rhceph-1.3-tools-rpms --disable=rhel-7-server-rhceph-1.3-installer-rpms --disable=rhel-7-server-rhceph-1.3-calamari-rpms
    Note

    If an ISO-based installation was performed for Red Hat Ceph Storage 1.3.x clients, then skip this first step.

  2. On the client node, enable the Tools repository.
  3. On the client node, update the ceph-common package:

    # yum update ceph-common

Any application depending on the Ceph client-side libraries will have to be restarted after upgrading the Ceph client package.

Note

For Nova compute nodes with running qemu-kvm instances or if using a dedicated qemu-kvm client, then stopping and starting the qemu-kvm instance processes is required. A simple restart will not work here.

5.2. Upgrading Between Minor Versions and Applying Asynchronous Updates

Important

Please contact Red Hat support prior to upgrading, if you have a large Ceph Object Gateway storage cluster with millions of objects present in buckets.

For more details refer to the Red Hat Ceph Storage 2.5 Release Notes, under the Slow OSD startup after upgrading to Red Hat Ceph Storage 2.5 heading.

Use the Ansible rolling_update.yml playbook located in the infrastructure-playbooks directory from the administration node to upgrade between two minor versions of Red Hat Ceph Storage 2 or to apply asynchronous updates.

Currently, this is the only supported way to upgrade to a minor version. If you use a cluster that was not deployed by using Ansible, see Section 3.1.7, “Taking over an Existing Cluster” for details on configuring Ansible to use a cluster that was deployed without it.

Ansible upgrades the Ceph nodes in the following order:

  • Monitor nodes
  • OSD nodes
  • MDS nodes
  • Ceph Object Gateway nodes
  • All other Ceph client nodes
Note

Upgrading encrypted OSD nodes is the same as upgrading OSD nodes that are not encrypted.

Before you Start

  • On the Ansible Administration node, enable the Red Hat Ceph Storage 2 Tools repository:

    # subscription-manager repos --enable=rhel-7-server-rhceph-2-tools-rpms
  • On the Ansible Administration node, ensure the latest version of ceph-ansible is installed:

    # yum update ceph-ansible
  • In the rolling_update.yml playbook, change the health_osd_check_retries and health_osd_check_delay values to 40 and 30 respectively. For each OSD node, Ansible will wait up to 20 minutes. Also, Ansible will check the cluster health every 30 seconds, waiting before continuing the upgrade process. Set the following values:

    health_osd_check_retries: 40
    health_osd_check_delay: 30
  • If the Ceph nodes are not connected to the Red Hat Content Delivery Network (CDN) and you used an ISO image to install Red Hat Ceph Storage, update the local repository with the latest version of Red Hat Ceph Storage. See Section 2.3, “Enabling the Red Hat Ceph Storage Repositories” for details.
  • If you upgrade from Red Hat Ceph Storage 2.1 to 2.2, review the Section 5.2.1, “Changes Between Ansible 2.1 and 2.2” section first. Ansible 2.2 uses slightly different file names and setting.

Procedure: Updating the Ceph Storage Cluster by using Ansible

  1. On the Ansible administration node, edit the /etc/ansible/hosts file with custom osd_scenarios if your cluster has any.
  2. On the Ansible administration node, navigate to the /usr/share/ceph-ansible/ directory:

    # cd /usr/share/ceph-ansible
  3. In the group_vars/all.yml file, uncomment the upgrade_ceph_packages option and set it to True:

    upgrade_ceph_packages: True
  4. In the group_vars/all.yml file, set generate_fsid to false.
  5. Get the current cluster fsid by executing ceph fsid. Set the retrieved fsid in group_vars/all.yml.
  6. If the cluster you want to upgrade contains any Ceph Object Gateway nodes, add the radosgw_interface parameter to the group_vars/all.yml file.

    radosgw_interface: <interface>

    Replace:

    • <interface> with the interface that the Ceph Object Gateway nodes listen to
  7. Run the rolling_update.yml playbook:

    # cp infrastructure-playbooks/rolling_update.yml .
    $ ansible-playbook rolling_update.yml

    When upgrading from version 2.4 to 2.5, run the playbook using the following command:

    $ ansible-playbook rolling_update.yml -e jewel_minor_update=true
  8. From the RBD mirroring daemon node, upgrade rbd-mirror manually:

    # yum upgrade rbd-mirror

    Restart the daemon:

    # systemctl restart  ceph-rbd-mirror@<client-id>
Important

The rolling_update.yml playbook includes the serial variable that adjusts the number of nodes to be updated simultaneously. Red Hat strongly recommends to use the default value (1), which ensures that hosts will be upgraded one by one.

5.2.1. Changes Between Ansible 2.1 and 2.2

Red Hat Ceph Storage 2.2 includes Ansible 2.2 that introduces the following changes:

  • Files in the group_vars directory have the .yml extension. Before updating to 2.2, you must rename them. To do so:

    Navigate to the Ansible directory:

    # cd usr/share/ceph-ansible

    Change the names of the files in group_vars:

    # mv groups_vars/all groups_vars/all.yml
    # mv groups_vars/mons groups_vars/mons.yml
    # mv groups_vars/osds groups_vars/osds.yml
    # mv groups_vars/mdss groups_vars/mdss.yml
    # mv groups_vars/rgws groups_vars/rgws.yml
  • Ansible 2.2 uses different variable names and handles this change automatically when updating to version 2.2. See Table 5.1, “Differences in Variable Names Between Ansible 2.1 and 2.2” table for details.

    Table 5.1. Differences in Variable Names Between Ansible 2.1 and 2.2

    Ansible 2.1 variable nameAnsible 2.2 variable name

    ceph_stable_rh_storage

    ceph_rhcs

    ceph_stable_rh_storage_version

    ceph_rhcs_version

    ceph_stable_rh_storage_cdn_install

    ceph_rhcs_cdn_install

    ceph_stable_rh_storage_iso_install

    ceph_rhcs_iso_install

    ceph_stable_rh_storage_iso_path

    ceph_rhcs_iso_path

    ceph_stable_rh_storage_mount_path

    ceph_rhcs_mount_path

    ceph_stable_rh_storage_repository_path

    ceph_rhcs_repository_path

Chapter 6. What to Do Next?

This is only the beginning of what Red Hat Ceph Storage can do to help you meet the challenging storage demands of the modern data center. Here are links to more information on a variety of topics:

Appendix A. Troubleshooting

A.1. Ansible Stops Installation Because It Detects Less Devices Than It Expected

The Ansible automation application stops the installation process and returns the following error:

- name: fix partitions gpt header or labels of the osd disks (autodiscover disks)
  shell: "sgdisk --zap-all --clear --mbrtogpt -- '/dev/{{ item.0.item.key }}' || sgdisk --zap-all --clear --mbrtogpt -- '/dev/{{ item.0.item.key }}'"
  with_together:
    - "{{ osd_partition_status_results.results }}"
    - "{{ ansible_devices }}"
  changed_when: false
  when:
    - ansible_devices is defined
    - item.0.item.value.removable == "0"
    - item.0.item.value.partitions|count == 0
    - item.0.rc != 0

What this means:

When the osd_auto_discovery parameter is set to true in the /etc/ansible/group_vars/osds.yml file, Ansible automatically detects and configures all the available devices. During this process, Ansible expects that all OSDs use the same devices. The devices get their names in the same order in which Ansible detects them. If one of the devices fails on one of the OSDs, Ansible fails to detect the failed device and stops the whole installation process.

Example situation:

  1. Three OSD nodes (host1, host2, host3) use the /dev/sdb, /dev/sdc, and dev/sdd disks.
  2. On host2, the /dev/sdc disk fails and is removed.
  3. Upon the next reboot, Ansible fails to detect the removed /dev/sdc disk and expects that only two disks will be used for host2, /dev/sdb and /dev/sdc (formerly /dev/sdd).
  4. Ansible stops the installation process and returns the above error message.

To fix the problem:

In the /etc/ansible/hosts file, specify the devices used by the OSD node with the failed disk (host2 in the Example situation above):

[osds]
host1
host2 devices="[ '/dev/sdb', '/dev/sdc' ]"
host3

See Installing Ceph Ansible for details.

Legal Notice

Copyright © 2018 Red Hat, Inc.
The text of and illustrations in this document are licensed by Red Hat under a Creative Commons Attribution–Share Alike 3.0 Unported license ("CC-BY-SA"). An explanation of CC-BY-SA is available at http://creativecommons.org/licenses/by-sa/3.0/. In accordance with CC-BY-SA, if you distribute this document or an adaptation of it, you must provide the URL for the original version.
Red Hat, as the licensor of this document, waives the right to enforce, and agrees not to assert, Section 4d of CC-BY-SA to the fullest extent permitted by applicable law.
Red Hat, Red Hat Enterprise Linux, the Shadowman logo, JBoss, OpenShift, Fedora, the Infinity logo, and RHCE are trademarks of Red Hat, Inc., registered in the United States and other countries.
Linux® is the registered trademark of Linus Torvalds in the United States and other countries.
Java® is a registered trademark of Oracle and/or its affiliates.
XFS® is a trademark of Silicon Graphics International Corp. or its subsidiaries in the United States and/or other countries.
MySQL® is a registered trademark of MySQL AB in the United States, the European Union and other countries.
Node.js® is an official trademark of Joyent. Red Hat Software Collections is not formally related to or endorsed by the official Joyent Node.js open source or commercial project.
The OpenStack® Word Mark and OpenStack logo are either registered trademarks/service marks or trademarks/service marks of the OpenStack Foundation, in the United States and other countries and are used with the OpenStack Foundation's permission. We are not affiliated with, endorsed or sponsored by the OpenStack Foundation, or the OpenStack community.
All other trademarks are the property of their respective owners.