Red Hat Ceph Storage 1.2.3 Installation Guide for CentOS (x86 64)

Red Hat Ceph Storage 1.2.3

Installing Calamari and Ceph Storage on CentOS x86_64.

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Abstract

This document provides instructions for preparing nodes before installation, for downloading Red Hat Ceph Storage, for setting up a local Red Hat Ceph Storage repository, for configuring Calamari, and for creating an initial Ceph Storage Cluster on CentOS 6.5.

Part I. Installation

Designed for cloud infrastructures and web-scale object storage, Red Hat® Ceph Storage is a massively scalable, open, software-defined storage platform that combines the most stable version of Ceph with a Ceph management platform, deployment tools, and support services. Providing the tools to flexibly and cost-effectively manage petabyte-scale data deployments in the enterprise, Red Hat Ceph Storage manages cloud data so enterprises can focus on managing their businesses.

This document provides procedures for installing Red Hat Ceph Storage v1.2.3 for x86_64 architecture on CentOS 6.

To simplify installation and to support deployment scenarios where security measures preclude direct Internet access, Red Hat Ceph Storage v1.2.3 is installed from a single software build delivered as an ISO with the ice_setup package, which installs the ice_setup script. When you execute the ice_setup script, it will install a local repository, the Calamari monitoring and administration server and the Ceph installation scripts, including a cephdeploy.conf file pointing ceph-deploy to the local repository.

We expect that you will have a dedicated administration node that will host the local repository and the Calamari monitoring and administration server. The following instructions assume you will install (or update) the repository on the dedicated administration node.

The administration/Calamari server hardware requirements vary with the size of your cluster. A minimum recommended hardware configuration for a Calamari server includes at least 4GB of RAM, a dual core CPU on x86_64 architecture and enough network throughput to handle communication with Ceph hosts. The hardware requirements scale linearly with the number of Ceph servers, so if you intend to run a fairly large cluster, ensure that you have enough RAM, processing power and network throughput.

Chapter 1. Pre-Installation Requirements

If you are installing Red Hat Ceph Storage v1.2.3 for the first time, you should review the pre-installation requirements first. Depending on your Linux distribution, you may need to adjust default settings and install required software before setting up a local repository and installing Calamari and Ceph.

1.1. Operating System

Red Hat Ceph Storage v1.2.3 and beyond requires a homogeneous operating system distribution and version e.g. CentOS 6 on x86_64 architecture for all Ceph nodes, including the Calamari cluster. We do not support clusters with heterogeneous operating systems and versions.

1.2. DNS Name Resolution

Ceph nodes must be able to resolve short host names, not just fully qualified domain names. Set up a default search domain to resolve short host names. To retrieve a Ceph node’s short host name, execute: 

hostname -s

Each Ceph node MUST be able to ping every other Ceph node in the cluster by its short host name.

1.3. NICs

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 OSDs. You SHOULD 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.

We DO NOT RECOMMEND using a single NIC for both a public and private network.

1.4. Network

Ensure that you configure your network interfaces and make them persistent so that the settings are identical on reboot. For example:

  • BOOTPROTO will usually be none for static IP addresses.
  • IPV6{opt} settings MUST be set to yes except for FAILURE_FATAL if you intend to use IPv6. You must also set your Ceph configuration file to tell Ceph to use IPv6 if you intend to use it. Otherwise, Ceph will use IPv4.
  • ONBOOT MUST be set to yes. If it is set to no, Ceph may fail to peer on reboot.

Navigate to /etc/sysconfig/network-scripts and ensure that the ifcfg-<iface> settings for your public and cluster interfaces (assuming you will use a cluster network too [RECOMMENDED]) are properly configured.

For details on configuring network interface scripts for CentOS 6, see Ethernet Interfaces.

1.5. Firewall for CentOS 6

The default firewall configuration for CentOS is fairly strict. You MUST adjust your firewall settings on the Calamari node to allow inbound requests on port 80 so that clients in your network can access the Calamari web user interface.

Calamari also communicates with Ceph nodes via ports 2003, 4505 and 4506. You MUST open ports 80, 2003, and 4505-4506 on your Calamari node. 

sudo iptables -I INPUT 1 -i <iface> -p tcp -s <ip-address>/<netmask> --dport 80 -j ACCEPT
sudo iptables -I INPUT 1 -i <iface> -p tcp -s <ip-address>/<netmask> --dport 2003 -j ACCEPT
sudo iptables -I INPUT 1 -i <iface> -m multiport -p tcp -s <ip-address>/<netmask> --dports 4505:4506 -j ACCEPT

You MUST open port 6789 on your public network on ALL Ceph monitor nodes. 

sudo iptables -I INPUT 1 -i <iface> -p tcp -s <ip-address>/<netmask> --dport 6789 -j ACCEPT

Finally, you MUST also open ports for OSD traffic (e.g., 6800-7100). Each OSD on each Ceph node needs three ports: one for talking to clients and monitors (public network); one for sending data to other OSDs (cluster network, if available; otherwise, public network); and, one for heartbeating (cluster network, if available; otherwise, public network). For example, if you have 4 OSDs, open 4 x 3 ports (12). 

sudo iptables -I INPUT 1 -i <iface> -m multiport -p tcp -s <ip-address>/<netmask> --dports 6800:6811 -j ACCEPT

Once you have finished configuring iptables, ensure that you make the changes persistent on each node so that they will be in effect when your nodes reboot. For example: 

/sbin/service iptables save

1.6. NTP

You MUST install Network Time Protocol (NTP) on all Ceph monitor hosts and ensure that monitor hosts are NTP peers. You SHOULD consider installing NTP on Ceph OSD nodes, but it is not required. NTP helps preempt issues that arise from clock drift.

  1. Install NTP 

    sudo yum install ntp

  2. Make sure NTP starts on reboot. 

    sudo chkconfig ntpd on

  3. Start the NTP service and ensure it’s running. 

    sudo /etc/init.d/ntpd start
sudo /etc/init.d/ntpd status

  4. Ensure that NTP is synchronizing Ceph monitor node clocks properly. 

    ntpq -p

For additional details on NTP for CentOS 6, see Network Time Protocol Setup.

1.7. Install SSH Server

For ALL Ceph Nodes perform the following steps:

  1. Install an SSH server (if necessary) on each Ceph Node: 

    sudo yum install openssh-server
  2. Ensure the SSH server is running on ALL Ceph Nodes.

For additional details on OpenSSH for CentOS 6, see OpenSSH.

1.8. Create a Ceph User

The ceph-deploy utility must login to a Ceph node as a user that has passwordless sudo privileges, because it needs to install software and configuration files without prompting for passwords.

ceph-deploy supports a --username option so you can specify any user that has password-less sudo (including root, although this is NOT recommended). To use ceph-deploy --username <username>, the user you specify must have password-less SSH access to the Ceph node, because ceph-deploy will not prompt you for a password.

We recommend creating a Ceph user on ALL Ceph nodes in the cluster. A uniform user name across the cluster may improve ease of use (not required), but you should avoid obvious user names, because hackers typically use them with brute force hacks (e.g., root, admin, <productname>). The following procedure, substituting <username> for the user name you define, describes how to create a user with passwordless sudo on a node called ceph-server.

  1. Create a user on each Ceph Node. : 

    ssh user@ceph-server
sudo useradd -d /home/<username> -m <username>
sudo passwd <username>

  2. For the user you added to each Ceph node, ensure that the user has sudo privileges. : 

    echo "<username> ALL = (root) NOPASSWD:ALL" | sudo tee /etc/sudoers.d/<username>
sudo chmod 0440 /etc/sudoers.d/<username>

1.9. Enable Password-less SSH

Since ceph-deploy will not prompt for a password, you must generate SSH keys on the admin node and distribute the public key to each Ceph node. ceph-deploy will attempt to generate the SSH keys for initial monitors.

  1. Generate the SSH keys, but do not use sudo or the root user. 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 with Create a Ceph User_. : 

    ssh-copy-id <username>@node1
ssh-copy-id <username>@node2
ssh-copy-id <username>@node3

  3. (Recommended) Modify the ~/.ssh/config file of your ceph-deploy admin node so that ceph-deploy can log in to Ceph nodes as the user you created without requiring you to specify --username <username> each time you execute ceph-deploy. This has the added benefit of streamlining ssh and scp usage. Replace <username> with the user name you created: 

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

1.10. Disable RAID

If you have RAID (not recommended), configure your RAID controllers to RAID 0 (JBOD).

1.11. Adjust PID Count

Hosts with high numbers of OSDs (e.g., > 20) may spawn a lot of threads, especially during recovery and re-balancing. Many Linux kernels default to a relatively small maximum number of threads (e.g., 32768). Check your default settings to see if they are suitable. 

cat /proc/sys/kernel/pid_max

Consider setting kernel.pid_max to a higher number of threads. The theoretical maximum is 4,194,303 threads. For example, you could add the following to the /etc/sysctl.conf file to set it to the maximum: 

kernel.pid_max = 4194303

To see the changes you made without a reboot, execute: 

sudo sysctl -p

To verify the changes, execute: 

sudo sysctl -a | grep kernel.pid_max

1.12. Hard Drive Prep on CentOS 6

Ceph aims for data safety, which means that when the Ceph Client receives notice that data was written to a storage drive, that data was actually written to the storage drive (i.e., it’s not in a journal or drive cache, but yet to be written). On CentOS 6, disable the write cache if the journal is on a raw drive.

Use hdparm to disable write caching on OSD storage drives: 

sudo hdparm -W 0 /<path-to>/<disk> 0

1.13. TTY

You may receive an error while trying to execute ceph-deploy commands. If requiretty is set by default on your Ceph hosts, disable it by executing sudo visudo and locate the Defaults requiretty setting. Change it to Defaults:ceph !requiretty where ceph is the user name from the step of Create a Ceph User to ensure that ceph-deploy can connect using the ceph user and execute commands as root.

1.14. SELinux

SELinux is set to Enforcing by default. For Ceph Storage v1.2.3, set SELinux to Permissive or disable it entirely and ensure that your installation and cluster is working properly. To set SELinux to Permissive, execute the following: 

sudo setenforce 0

To configure SELinux persistently, modify the configuration file at /etc/selinux/config.

1.15. Disable EPEL on Ceph Cluster Nodes

Some Ceph package dependencies require versions that differ from the package versions from EPEL. Disable EPEL to ensure that you install the packages required for use with Ceph.

Chapter 2. Setting Up Your Administration Server

Red Hat Ceph Storage uses an administration server for a Red Hat Ceph Storage repository, the Calamari monitoring and administration server, and your cluster’s Ceph configuration and authentication keys.

Visit https://access.redhat.com/articles/1560193 to obtain the Red Hat Ceph Storage installation ISO image file for CentOS 6.

Execute the following steps:

  1. Download the rhceph-1.2.3-centos-6-x86_64.iso file.

  2. Using sudo, mount the image: 

    sudo mount -o loop <path_to_iso>/rhceph-1.2.3-centos-6-x86_64.iso /mnt

  3. Using sudo, install the setup script. 

    sudo yum install /mnt/ice_setup-*.rpm

  4. Create a working directory for your Ceph cluster configuration files and keys. Then, navigate to that directory. For example: 

    mkdir ~/ceph-config
cd ~/ceph-config

  5. Using sudo, run the setup script in the working directory. NOTE: You cannot run the setup script in /mnt or a read-only directory or the script will crash. The script will output a cephdeploy.conf file, which ceph-deploy will use to point to the local repository. 

    sudo ice_setup -d /mnt

    The setup script performs the following operations:

    • It moves the RPMs to /opt/ICE and /opt/calamari
    • It creates a .repo file for the ceph-deploy and calamari packages pointing to a local path
    • It installs the Calamari server packages on the admin node
    • It installs the ceph-deploy package on the admin node; and
    • It writes a cephdeploy.conf file to /opt/ICE.

  6. Using sudo, initialize the Calamari monitoring and administration server. 

    sudo calamari-ctl initialize
    Note

    The initialization script implies that you can only execute ceph-deploy when pointing to a remote site. You may also direct ceph-deploy to your Calamari admin node (e.g,. ceph-deploy admin <admin-hostname>). You can also use the Calamari admin node to run a Ceph daemon, although this is not recommended.

At this point, you should be able to access the Calamari web server via a web browser. Proceed to Storage Cluster Quick Start guide.

Part II. Storage Cluster Quick Start

This Quick Start sets up a Red Hat Ceph Storage cluster using ceph-deploy on your Calamari admin node. Create a small Ceph cluster so you can explore Ceph functionality. As a first exercise, create a Ceph Storage Cluster with one Ceph Monitor and some Ceph OSD Daemons, each on separate nodes. Once the cluster reaches an active + clean state, you can use the cluster.

Diagram

Chapter 3. Executing ceph-deploy

When executing ceph-deploy with Red Hat Ceph Storage, ceph-deploy will need to retrieve Ceph packages from the /opt/ICE directory on your Calamari admin host, so you need to ensure that ceph-deploy has access to the cephdeploy.conf file that was written to your local working directory when you executed calamari-ctl initialize. 

cd ~/ceph-config
Important

The ceph-deploy utility does not issue sudo commands needed on the remote host. Execute ceph-deploy commands as a regular user (not as root or using sudo). The Create a Ceph User and Enable Password-less SSH steps enable ceph-deploy to execute as root without sudo and without connecting to Ceph nodes as the root user.

The ceph-deploy utility will output files to the current directory. Ensure you are in this directory when executing ceph-deploy, and ensure that ceph-deploy points to the cephdeploy.conf file generated by calamari-ctl initialize when installing Red Had Ceph Storage packages.

Chapter 4. Create a Cluster

If at any point you run into trouble and you want to start over, execute the following to purge the configuration: 

ceph-deploy purgedata <ceph-node> [<ceph-node>]
ceph-deploy forgetkeys

To purge the Ceph packages too, you may also execute: 

ceph-deploy purge <ceph-node> [<ceph-node>]

If you execute purge, you must re-install Ceph.

On your Calamari admin node from the directory you created for holding your configuration details, perform the following steps using ceph-deploy.

  1. Create the cluster. : 

    ceph-deploy new <initial-monitor-node(s)>

    For example: 

    ceph-deploy new node1

    Check the output of ceph-deploy with ls and cat in the current directory. You should see a Ceph configuration file, a monitor secret keyring, and a log file of the ceph-deploy procedures.

    At this stage, you may begin editing your Ceph configuration file.

    Note

    If you choose not to use ceph-deploy you will have to deploy Ceph manually or refer to Ceph manual deployment documentation and configure a deployment tool (e.g., Chef, Juju, Puppet, etc.) to perform each operation ceph-deploy performs for you.

  2. Add the public_network and cluster_network settings under the [global] section of your Ceph configuration file. 

    public_network = <ip-address>/<netmask>
cluster_network = <ip-address>/<netmask>

    These settings distinguish which network is public (front-side) and which network is for the cluster (back-side). Ensure that your nodes have interfaces configured for these networks. We do not recommend using the same NIC for the public and cluster networks.

  3. Turn on IPv6 if you intend to use it. 

    ms_bind_ipv6 = true

  4. Add or adjust the osd journal size setting under the [global] section of your Ceph configuration file. 

    osd_journal_size = 10000

    We recommend a general setting of 10GB. Ceph’s default osd_journal_size is 0, so you will need to set this in your ceph.conf file. A journal size should find the product of the filestore_max_sync_interval and the expected throughput, and multiply the product by two (2). The expected throughput number should include the expected disk throughput (i.e., sustained data transfer rate), and network throughput. For example, a 7200 RPM disk will likely have approximately 100 MB/s. Taking the min() of the disk and network throughput should provide a reasonable expected throughput.

  5. Set the number of copies to store (default is 3) and the default minimum required write data when in a degraded state (default is 2) under the [global] section of your Ceph configuration file. We recommend the default values for production clusters. 

    osd_pool_default_size = 3
osd_pool_default_min_size = 2

    For a quick start, you may wish to set osd_pool_default_size to 2, and the osd_pool_default_min_size to 1 so that you can achieve and active+clean state with only two OSDs.

    These settings establish the networking bandwidth requirements for the cluster network, and the ability to write data with eventual consistency (i.e., you can write data to a cluster in a degraded state if it has min_size copies of the data already).

  6. Set the default number of placement groups (osd_pool_default_pg_num) and placement groups for placement (osd_pool_default_pgp_num) for a pool under the [global] section of your Ceph configuration file. The number you specify depends upon the number of OSDs in your cluster. For small clusters (< 5 OSDs) we recommend 128 placement groups per pool. The osd_pool_default_pg_num and osd_pool_default_pgp_num value should be equal. 

    osd_pool_default_pg_num = <n>
osd_pool_default_pgp_num = <n>
    • Less than 5 OSDs set pg_num and pgp_num to 128
    • Between 5 and 10 OSDs set pg_num and pgp_num to 512
    • Between 10 and 50 OSDs set pg_num and pgp_num to 4096

    • If you have more than 50 OSDs, you need to understand the tradeoffs and how to calculate the pg_num and pgp_num values. Generally, you may use the formula: 

                   (OSDs * 100)
Total PGs =  ------------
              pool size

      Where the pool size in the formula above is the osd_pool_default_size value you set in the preceding step. For best results, round the result of this formula up to the nearest power of two. It is an optional step, but it will help CRUSH balance objects evenly across placement groups.

  7. Set the maximum number of placement groups per OSD. The Ceph Storage Cluster has a default maximum value of 300 placement groups per OSD. You can set a different maximum value in your Ceph configuration file. 

    mon_pg_warn_max_per_osd

    Multiple pools can use the same CRUSH ruleset. When an OSD has too many placement groups associated to it, Ceph performance may degrade due to resource use and load. This setting warns you, but you may adjust it to your needs and the capabilities of your hardware.

  8. Set a CRUSH leaf type to the largest serviceable failure domain for your replicas under the [global] section of your Ceph configuration file. The default value is 1, or host, which means that CRUSH will map replicas to OSDs on separate separate hosts. For example, if you want to make three object replicas, and you have three racks of chassis/hosts, you can set osd_crush_chooseleaf_type to 3, and CRUSH will place each copy of an object on OSDs in different racks. For example: 

    osd_crush_chooseleaf_type = 3

    The default CRUSH hierarchy types are:

    • type 0 osd
    • type 1 host
    • type 2 chassis
    • type 3 rack
    • type 4 row
    • type 5 pdu
    • type 6 pod
    • type 7 room
    • type 8 datacenter
    • type 9 region
    • type 10 root

  9. Set max_open_files so that Ceph will set the maximum open file descriptors at the OS level to help prevent Ceph OSD Daemons from running out of file descriptors. 

    max_open_files = 131072

  10. We recommend having settings for clock drift in your Ceph configuration in addition to setting up NTP on your monitor nodes, because clock drift is a common reason monitors fail to achieve a consensus on the state of the cluster. We recommend having the report time out and down out interval in the Ceph configuration file so you have a reference point for how long an OSD can be down before the cluster starts re-balancing. 

    mon_clock_drift_allowed = .15
mon_clock_drift_warn_backoff = 30
mon_osd_down_out_interval = 300
mon_osd_report_timeout = 300

  11. Set the full_ratio and near_full_ratio to acceptable values. They default to full at 95% and near full at 85% by default. You may also set backfill_full_ratio so that OSDs don’t accept backfill requests when they are already near capacity. 

    mon_osd_full_ratio = .75
mon_osd_nearfull_ratio = .65
osd_backfill_full_ratio = .65

    Consider the amount of storage capacity that would be unavailable during the failure of a large-grained failure domain such as a rack (e.g., the failure of a power distribution unit or a rack switch). You should consider the cost/benefit tradeoff of having that amount of extra capacity available for the failure of a large-grained failure domain if you have stringent high availability requirements. As a best practice, as you get close to reaching the full ratio, you should start receiving "near full" warnings so that you have ample time to provision additional hardware for your cluster. "Near full" warnings may be annoying, but they are not as annoying as an interruption of service.

    Important

    When your cluster reaches its full ratio, Ceph prevents clients from accessing the cluster to ensure data durability. This results in a service interruption, so you should carefully consider the implications of capacity planning and the implications of reaching full capacity—​especially in view of failure.

In summary, your initial Ceph configuration file should have at least the following settings with appropriate values assigned after the = sign: 

[global]
fsid = <cluster-id>
mon_initial_members = <hostname>[, <hostname>]
mon_host = <ip-address>[, <ip-address>]
public_network = <network>[, <network>]
cluster_network = <network>[, <network>]
ms_bind_ipv6 = [true | false]
max_open_files = 131072
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>
mon_osd_full_ratio = <n>
mon_osd_nearfull_ratio = <n>
osd_backfill_full_ratio = <n>
mon_clock_drift_allowed = .15
mon_clock_drift_warn_backoff = 30
mon_osd_down_out_interval = 300
mon_osd_report_timeout = 300

Chapter 5. Install Ceph

Ensure that ceph-deploy is pointing to the cephdeploy.conf file generated by calamari-ctl initialize (e.g., in the exemplary ~/ceph-config directory, the /opt/ICE directory, etc.). Otherwise, you may not receive packages from the local repository. Ideally, you should run ceph-deploy from the directory where you keep your configuration (e.g., the examplary ~/ceph-config) so that you can maintain a {cluster-name}.log file with all the commands you have executed with ceph-deploy. To install Ceph on remote nodes, first use --repo option with ceph-deploy to install the repo files on remote nodes.

For admin node, execute: 

ceph-deploy install <ceph-node>

For example: 

ceph-deploy install admin-node

For other nodes, execute: 

ceph-deploy install --repo <ceph-node> [<ceph-node> ...]
ceph-deploy install <ceph-node> [<ceph-node> ...]

For example: 

ceph-deploy install --repo node1 node2 node3 node4
ceph-deploy install node1 node2 node3 node4

The ceph-deploy utility will install Ceph on each node. NOTE: If you use ceph-deploy purge, you must re-execute these steps to re-install Ceph.

Chapter 6. Add Initial Monitors

Add the initial monitor(s) and gather the keys. 

ceph-deploy mon create-initial

Once you complete the process, your local directory should have the following keyrings:

  • <cluster-name>.client.admin.keyring
  • <cluster-name>.bootstrap-osd.keyring
  • <cluster-name>.bootstrap-mds.keyring

Chapter 7. Connect Monitor Hosts to Calamari

Once you have added the initial monitor(s), you need to connect the monitor hosts to Calamari. 

ceph-deploy calamari connect <ceph-node>[<ceph-node> ...]

For example, using the exemplary node1 from above, you would execute: 

ceph-deploy calamari connect node1

If you expand your monitor cluster with additional monitors, you will have to connect the hosts that contain them to Calamari, too.

Chapter 8. Make your Calamari Admin Node a Ceph Admin Node

After you create your initial monitors, you can use the Ceph CLI to check on your cluster. However, you have to specify the monitor and admin keyring each time with the path to the directory holding your configuration, but you can simplify your CLI usage by making the admin node a Ceph admin client.

Note

You will also need to install ceph or ceph-common on the Calamari node. 

ceph-deploy admin <node-name>

For example: 

ceph-deploy admin admin-node

The ceph-deploy utility will copy the ceph.conf and ceph.client.admin.keyring files to the etc/ceph directory. When ceph-deploy is talking to the local admin host (admin-node), it must be reachable by its hostname (e.g., hostname -s). If necessary, modify /etc/hosts to add the name of the admin host. If you do not have an /etc/ceph directory, you should install ceph-common.

You may then use the Ceph CLI.

Once you have added your new Ceph monitors, Ceph will begin synchronizing the monitors and form a quorum. You can check the quorum status by executing the following: 

sudo ceph quorum_status --format json-pretty

Ensure that you have acceptable permissions for the /etc/ceph/ceph.client.admin.keyring. You can use sudo when executing the ceph command, or your can change the keyring permissions to enable a specific user or group. Keyring permissions provide administrative capability to the Red Hat Ceph Storage cluster. So exercise caution if many users have access to the Ceph nodes and admin node. 

sudo chmod +r /etc/ceph/ceph.client.admin.keyring
Note

Your cluster will not achieve an active + clean state until you add enough OSDs to facilitate object replicas. This is inclusive of CRUSH failure domains.

Chapter 9. Add OSDs

Before creating OSDs, consider the following:

  • We recommend using the XFS filesystem (default).
  • We recommend using SSDs for journals. It is common to partition SSDs to serve multiple OSDs. Ensure that the number of SSD partitions does not exceed your SSD’s sequential write limits. Also, ensure that SSD partitions are properly aligned, or their write performance will suffer.
  • We recommend using ceph-deploy disk zap on a Ceph OSD drive before executing ceph-deploy osd create. For example: 
ceph-deploy disk zap <ceph-node>:<data-drive>

From your admin node, use ceph-deploy to prepare the OSDs. 

ceph-deploy osd prepare <ceph-node>:<data-drive>:<journal-partition> [<ceph-node>:<data-drive>:<journal-partition>]

For example: 

ceph-deploy osd prepare node2:sdb:ssdb node3:sdd:ssdb node4:sdd:ssdb

In the foregoing example, sdb is a spinning hard drive. Ceph will use the entire drive for OSD data. ssdb is a partition on an SSD drive, which Ceph will use to store the journal for the OSD.

Once you prepare OSDs, use ceph-deploy to activate the OSDs. 

ceph-deploy osd activate <ceph-node>:<data-drive>:<journal-partition> [<ceph-node>:<data-drive>:<journal-partition>]

For example: 

ceph-deploy osd activate node2:sdb:ssdb node3:sdd:ssdb node4:sdd:ssdb

To achieve an active + clean state, you must add as many OSDs as the value of osd pool default size = <n> from your Ceph configuration file.

Chapter 10. Connect OSD Hosts to Calamari

Once you have added the initial OSDs, you need to connect the OSD hosts to Calamari. 

ceph-deploy calamari connect <ceph-node>[<ceph-node> ...]

For example, using the exemplary node2, node3 and node4 from above, you would execute: 

ceph-deploy calamari connect node2 node3 node4

As you expand your cluster with additional OSD hosts, you will have to connect the hosts that contain them to Calamari, too.

Chapter 11. Create a CRUSH Hierarchy

You can run a Ceph cluster with a flat node-level hierarchy (default). This is NOT RECOMMENDED. We recommend adding named buckets of various types to your default CRUSH hierarchy. This will allow you to establish a larger-grained failure domain, usually consisting of racks, rows, rooms and data centers. 

ceph osd crush add-bucket <bucket-name> <bucket-type>

For example: 

ceph osd crush add-bucket dc1 datacenter
ceph osd crush add-bucket room1 room
ceph osd crush add-bucket row1 row
ceph osd crush add-bucket rack1 rack
ceph osd crush add-bucket rack2 rack
ceph osd crush add-bucket rack3 rack

Then, place the buckets into a hierarchy: 

ceph osd crush move dc1 root=default
ceph osd crush move room1 datacenter=dc1
ceph osd crush move row1 room=room1
ceph osd crush move rack1 row=row1
ceph osd crush move node2 rack=rack1

Chapter 12. Add OSD Hosts/Chassis to the CRUSH Hierarchy

Once you have added OSDs and created a CRUSH hierarchy, add the OSD hosts/chassis to the CRUSH hierarchy so that CRUSH can distribute objects across failure domains. For example: 

ceph osd crush set osd.0 1.0 root=default datacenter=dc1 room=room1 row=row1 rack=rack1 host=node2
ceph osd crush set osd.1 1.0 root=default datacenter=dc1 room=room1 row=row1 rack=rack2 host=node3
ceph osd crush set osd.2 1.0 root=default datacenter=dc1 room=room1 row=row1 rack=rack3 host=node4

The foregoing example uses three different racks for the exemplary hosts (assuming that is how they are physically configured). Since the exemplary Ceph configuration file specified "rack" as the largest failure domain by setting osd_crush_chooseleaf_type = 3, CRUSH can write each object replica to an OSD residing in a different rack. Assuming osd_pool_default_min_size = 2, this means (assuming sufficient storage capacity) that the Ceph cluster can continue operating if an entire rack were to fail (e.g., failure of a power distribution unit or rack router).

Chapter 13. Check CRUSH Hierarchy

Check your work to ensure that the CRUSH hierarchy is accurate. 

ceph osd tree

If you are not satisfied with the results of your CRUSH hierarchy, you may move any component of your hierarchy with the move command. 

ceph osd crush move <bucket-to-move> <bucket-type>=<parent-bucket>

If you want to remove a bucket (node) or OSD (leaf) from the CRUSH hierarchy, use the remove command: 

ceph osd crush remove <bucket-name>

Chapter 14. Check Cluster Health

To ensure that the OSDs in your cluster are peering properly, execute: 

ceph health

You may also check on the health of your cluster using the Calamari dashboard.

Chapter 15. List/Create a Pool

You can manage pools using Calamari, or using the Ceph command line. Verify that you have pools for writing and reading data: 

ceph osd lspools

You can bind to any of the pools listed using the admin user and client.admin key. To create a pool, use the following syntax: 

ceph osd pool create <pool-name> <pg-num> [<pgp-num>] [replicated] [crush-ruleset-name]

For example: 

ceph osd pool create mypool 512 512 replicated replicated_ruleset
Note

To find the rule set names available, execute ceph osd crush rule list.

Chapter 16. Storing/Retrieving Object Data

To perform storage operations with Ceph Storage Cluster, all Ceph clients regardless of type must:

  1. Connect to the cluster.
  2. Create an I/O contest to a pool.
  3. Set an object name.
  4. Execute a read or write operation for the object.

The Ceph Client retrieves the latest cluster map and the CRUSH algorithm calculates how to map the object to a placement-group, and then calculates how to assign the placement group to a Ceph OSD Daemon dynamically. Client types such as Ceph Block Device and the Ceph Object Gateway perform the last two steps transparently.

To find the object location, all you need is the object name and the pool name. For example: 

ceph osd map <poolname> <object-name>
Note

The rados CLI tool in the following example is for Ceph administrators only.

Exercise: Locate an Object
As an exercise, lets create an object. Specify an object name, a path to a test file containing some object data and a pool name using the rados put command on the command line. For example: 
echo <Test-data> > testfile.txt
rados put <object-name> <file-path> --pool=<pool-name>
rados put test-object-1 testfile.txt --pool=data

To verify that the Ceph Storage Cluster stored the object, execute the following: 

rados -p data ls

Now, identify the object location: 

ceph osd map <pool-name> <object-name>
ceph osd map data test-object-1

Ceph should output the object’s location. For example: 

osdmap e537 pool 'data' (0) object 'test-object-1' -> pg 0.d1743484 (0.4) -> up [1,0] acting [1,0]

To remove the test object, simply delete it using the rados rm command. For example: 

rados rm test-object-1 --pool=data

As the cluster size changes, the object location may change dynamically. One benefit of Ceph’s dynamic rebalancing is that Ceph relieves you from having to perform the migration manually.

Part III. Upgrading Ceph

You may upgrade your administration server and your Ceph Storage cluster when Red Hat provides fixes or delivers a major release.

Chapter 17. Upgrading Your Cluster from v1.2.2 to v1.2.3

Upgrade the administration server first to support upgrading other daemons in the cluster.

Remove calamari-server, ceph, and ceph-deploy repositories under /etc/yum.repos.d directory from previous installation, download and mount the latest Ceph ISO, run ice_setup, re-initialize Calamari and upgrade Ceph.

Remove the ceph related repositories under /etc/yum.repos.d. For example: 

cd /etc/yum.repos.d
sudo rm calamari-server.repo ceph.repo ceph-deploy.repo

To obtain the Red Hat Ceph Storage installation ISO image files for the newer version, visit https://access.redhat.com/articles/1560193.

Execute the following steps:

  1. Download the rhceph-1.2.3-centos-6-x86_64.iso file.

  2. Using sudo, mount the image: 

    sudo mount -o loop <path_to_iso>/rhceph-1.2.3-centos-6-x86_64.iso /mnt

  3. Using sudo, install the setup script. 

    sudo yum install /mnt/ice_setup-*.rpm
  4. Back up your Ceph configuration, log and key files.

  5. Change to your working directory. For example: 

    cd ~/ceph-config

  6. Run ice_setup: 

    sudo ice_setup -d /mnt

    The ice_setup program will install upgraded version of ceph-deploy, calamari server, create new local repositories and a cephdeploy.conf file.

  7. Restart Apache: 

    sudo service httpd restart

  8. Restart Calamari: 

    sudo calamari-ctl initialize

  9. Upgrade Ceph: 

    ceph-deploy install <admin node>
  10. To upgrade the Ceph daemons running on your cluster hosts, see Storage Cluster Upgrade section for details.

Chapter 18. Storage Cluster Upgrade

Upgrading Ceph daemons involves installing the upgraded packages, and restarting each Ceph daemon. We recommend upgrading in this order:

  • Ceph Monitors
  • Ceph OSD Daemons

  • Ceph Object Gateways

    1. To upgrade monitors, first remove existing Ceph repos.

      From monitor node, execute: 

      cd /etc/yum.repos.d/
sudo rm -rf calamari-minion.repo ceph.repo

      Then, execute the following from your admin node: 

      ceph-deploy install --repo <ceph-node>[<ceph-node> ...]
ceph-deploy install <ceph-node>[<ceph-node> ...]

      ceph-deploy will install the latest version of Ceph.

      Although your monitor node is already connected with Calamari node from the previous installation, you need to reconnect your monitor node to the Calamari to get the latest salt-minion package.

      Execute from your admin node: 

      ceph-deploy calamari connect <ceph-node>

      From the monitor node, restart the Ceph Monitor daemon: 

      sudo /etc/init.d/ceph [options] restart mon.[id]

      Upgrade each monitor one at a time, and allow the monitor to come up and in, rejoining the monitor quorum, before proceeding to upgrade the next monitor.

    2. To upgrade OSDs, first remove existing Ceph repos.

      From OSD node, execute: 

      cd /etc/yum.repos.d/
sudo rm -rf calamari-minion.repo ceph.repo

      Then, execute the following from your admin node: 

      ceph-deploy install --repo <ceph-node>[<ceph-node> ...]
ceph-deploy install <ceph-node>[<ceph-node> ...]

      ceph-deploy will install the latest version of Ceph.

      Although your OSD node is already connected with Calamari node from the previous installation, you need to reconnect your OSD node to the Calamari node to get the latest salt-minion package.

      Execute from your admin node: 

      ceph-deploy calamari connect <ceph-node>

      We recommend upgrading OSDs by CRUSH hierarchy—​i.e., by failure domain or performance domain. Give each daemon time to come up and in with the cluster reaching a HEALTH_OK state before proceeding to the next CRUSH hierarchy. To restart an OSD, execute ceph with the restart command. Use the following syntax: 

      sudo /etc/init.d/ceph [options] restart osd.[id]

    3. To upgrade a Ceph Object Gateway daemon, first remove existing Ceph repos (if any).

      From gateway node, execute: 

      cd /etc/yum.repos.d/
sudo rm -rf ceph.repo

      Then, execute the following from your admin node: 

      ceph-deploy install --repo <gateway-node>

      Then upgrade the ceph-radosgw package. Execute from your gateway node: 

      sudo yum install ceph-radosgw

      To upgrade the Ceph Object Gateway synchronization agent, execute from your gateway node: 

      sudo yum install radosgw-agent

      Restart each Ceph Object gateway daemon. To do so, execute the following on each gateway node: 

      sudo service ceph-radosgw restart

      If you are running a federated architecture, restart your sync agent(s). For data replication agents, go to the terminal and execute ctrl + c; then, execute: 

      radosgw-agent -c [config-file]

      For metadata replication agents, go to the terminal and execute ctrl + c; then, execute: 

      radosgw-agent -c [config-file] --metadata-only

Part IV. Upgrade Ceph Cluster on CentOS 6 to RHEL 7

If you have a Inktank Ceph Enterprise (ICE) v1.2.2 cluster running on CentOS 6 and you are planning to upgrade to Red Hat Ceph Storage (RHCS) v1.3 on RHEL 7, you need to have the following approach:

  • Upgrade your cluster from v1.2.2 to v1.2.3 on CentOS 6
  • Upgrade your OS from CentOS 6 to RHEL 6
  • Upgrade your OS from RHEL 6 to RHEL 7
  • Upgrade your cluster from v1.2.3 to v1.3 on RHEL 7
Note

ICE v1.2.2 can run on RHEL 7.0, but not on RHEL 7.1. So, we recommend to upgrade your cluster to 1.2.3 while on CentOS.

The sections given below will guide you to upgrade your ICE v1.2.2 cluster on CentOS 6.6 to RHCS v1.3 on RHEL 7.1.

Chapter 19. Upgrading Your Cluster from v1.2.2 to v1.2.3

To upgrade your cluster from v1.2.2 to v1.2.3 on CentOS, follow the steps mentioned in Upgrade to RHCS v1.2.3 on CentOS 6.

Chapter 20. Upgrading Your OS From CentOS 6.6 to RHEL 6.6

To upgrade your OS from CentOS 6.6 to RHEL 6.6, we recommend upgrading in the following sequence:

  • Admin Node
  • Monitor Nodes
  • OSD Nodes
  • Ceph Object Gateway Nodes.

Before starting the OS upgrade, stop your Ceph cluster. Execute: 

sudo /etc/init.d/ceph -a stop

Once you execute with -a (i.e., execute on all nodes), Ceph should stop operating.

For ease of understanding, we will divide the upgrade section into three sub sections, viz:

  • Prerequisites
  • Download of RHEL packages
  • Upgrade to RHEL 6.6

20.1. Prerequisite

  1. Update your OS to ensure it runs the latest kernel available. Execute: 

    sudo yum update
sudo reboot

  2. Install packages that will be required by various Red Hat Network tools: 

    sudo yum install dbus-python libxml2-python m2crypto pyOpenSSL python-dmidecode python-ethtool python-gudev usermode

  3. Create a rhel directory: 

    sudo mkdir /rhel

20.2. Download of RHEL packages

  1. Log into Red Hat Customer Service Portal with your RHN account credentials.
  2. Click Downloads to visit the Software & Download Center.
  3. Click on Red Hat Enterprise Linux to visit it’s download page.
  4. Select Version as 6.6 from the drop-down list and click on Packages tab below.

  5. Use the Filter text box on the right hand side, search for and download the latest version of the following packages for RHEL 6.6 x86_64 in your rhel directory:

    • redhat-release-server
    • rhn-check
    • rhn-client-tools
    • rhnlib
    • rhnsd
    • rhn-setup
    • yum
    • yum-metadata-parser
    • yum-rhn-plugin
    • yum-utils

  6. Install the Red Hat GnuPG signing key: 

    cd /rhel
sudo wget https://www.redhat.com/security/fd431d51.txt
sudo rpm --import fd431d51.txt

20.3. Upgrade to RHEL 6.6

  1. Forcibly remove the package that identifies the current system as CentOS: 

    sudo rpm -e --nodeps centos-release

  2. Forcibly upgrade to the downloaded RHEL and RHN packages: 

    sudo rpm -Uhv --force *.rpm
sudo rpm -e yum-plugin-fastestmirror
sudo yum clean all

  3. Register the system with Red Hat Network: 

    sudo rhn_register

  4. Update your system with the new yum repository: 

    sudo yum update

Once, you have upgraded your OS to RHEL 6.6, start ceph from your admin node and check if it is running properly.

Execute: 

sudo /etc/init.d/ceph -a start

Chapter 21. Upgrading Your OS From RHEL 6.6 to RHEL 7.1

To upgrade your OS from RHEL 6.6 to RHEL 7.1, we recommend upgrading in the following sequence:

  • Admin Node
  • Monitor Nodes
  • OSD Nodes
  • Ceph Object Gateway Nodes.

Before starting the OS upgrade, stop your Ceph cluster. Execute: 

sudo /etc/init.d/ceph -a stop

Once you execute with -a (i.e., execute on all nodes), Ceph should stop operating.

Then, follow the steps mentioned in Upgrade from RHEL 6 to RHEL 7 to upgrade your OS to RHEL 7.1

Note

You can either use a migration script or use preupgrade-assistant followed by manual steps to upgrade your OS from RHEL 6 to RHEL 7. In case, you encounter a issue while upgrading, please contact Red Hat Support to assist you in the OS upgrade process.

Once, you have upgraded your OS to RHEL 7.1, start ceph from your admin node.

Execute: 

sudo /etc/init.d/ceph -a start

Chapter 22. Upgrading Your Cluster from v1.2.3 to v1.3

To upgrade your cluster from v1.2.3 to v1.3 on RHEL 7.1, follow the steps mentioned in Upgrade to RHCS v1.3 on RHEL 7.

On succesful completion of this last section, now you should have a RHCS v1.3 cluster on RHEL 7.1.