Chapter 3. Deploying Red Hat Ceph Storage

This chapter describes how to use the Ansible application to deploy a Red Hat Ceph Storage cluster and other components, such as Metadata Servers or the Ceph Object Gateway.

To install a Red Hat Ceph Storage cluster, see Section 3.2, “Installing a Red Hat Ceph Storage Cluster”.
To install Metadata Servers, see Section 3.4, “Installing Metadata Servers”.
To install the ceph-client role, see Section 3.5, “Installing the Ceph Client Role”.
To install the Ceph Object Gateway, see Section 3.6, “Installing the Ceph Object Gateway”.
To configure a multisite Ceph Object Gateway, see Section 3.6.1, “Configuring a multisite Ceph Object Gateway”.
To learn about the Ansible --limit option, see Section 3.8, “Understanding the limit option”.

Previously, Red Hat did not provide the ceph-ansible package for Ubuntu. In Red Hat Ceph Storage version 3 and later, you can use the Ansible automation application to deploy a Ceph cluster from an Ubuntu node.

3.1. Prerequisites

Obtain a valid customer subscription.
Prepare the cluster nodes. On each node:

3.2. Installing a Red Hat Ceph Storage Cluster

Use the Ansible application with the ceph-ansible playbook to install Red Hat Ceph Storage 3.

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

Prerequisites

On the Ansible administration node, install the ceph-ansible package:
```
[user@admin ~]$ sudo apt-get install ceph-ansible
```

Procedure

Run the following commands from the Ansible administration node unless instructed otherwise.

As the Ansible user, create the ceph-ansible-keys directory where Ansible stores temporary values generated by the ceph-ansible playbook.
```
[user@admin ~]$ mkdir ~/ceph-ansible-keys
```
As root, create a symbolic link to the /usr/share/ceph-ansible/group_vars directory in the /etc/ansible/ directory:
```
[root@admin ~]# ln -s /usr/share/ceph-ansible/group_vars /etc/ansible/group_vars
```
Navigate to the /usr/share/ceph-ansible/ directory:
```
[root@admin ~]$ cd /usr/share/ceph-ansible
```

Create new copies of the yml.sample files:

[root@admin ceph-ansible]# cp group_vars/all.yml.sample group_vars/all.yml
[root@admin ceph-ansible]# cp group_vars/osds.yml.sample group_vars/osds.yml
[root@admin ceph-ansible]# cp site.yml.sample site.yml

Edit the copied files.

Edit the group_vars/all.yml file. See the table below for the most common required and optional parameters to uncomment. Note that the table does not include all parameters.

Important

Do not set the cluster: ceph parameter to any value other than ceph because using custom cluster names is not supported.

Table 3.1. General Ansible Settings

Option	Value	Required	Notes
`ceph_origin`	`repository` or `distro` or `local`	Yes	The `repository` value means Ceph will be installed through a new repository. The `distro` value means that no separate repository file will be added, and you will get whatever version of Ceph that is included with the Linux distribution. The `local` value means the Ceph binaries will be copied from the local machine.
`ceph_repository_type`	`cdn` or `iso`	Yes
`ceph_rhcs_iso_path`	The path to the ISO image	Yes if using an ISO image
`ceph_rhcs_cdn_debian_repo`	The credentials to access the online Ubuntu Ceph repositories. For example, `https://username:password@rhcs.download.redhat.com`.	Yes
`ceph_rhcs_cdn_debian_repo_version`	Use `/3-release/` for new installations; use `/3-updates/` for updates.	Yes
`monitor_interface`	The interface that the Monitor nodes listen to	`monitor_interface`, `monitor_address`, or `monitor_address_block` is required
`monitor_address`	The address that the Monitor nodes listen to
`monitor_address_block`	The subnet of the Ceph public network		Use when the IP addresses of the nodes are unknown, but the subnet is known
`ip_version`	`ipv6`	Yes if using IPv6 addressing
`public_network`	The IP address and netmask of the Ceph public network, or the corresponding IPv6 address if using IPv6	Yes	Section 2.7, “Verifying the Network Configuration for Red Hat Ceph Storage”
`cluster_network`	The IP address and netmask of the Ceph cluster network	No, defaults to `public_network`

An example of the all.yml file can look like:

ceph_origin: repository
ceph_repository: rhcs
ceph_repository_type: cdn
ceph_rhcs_version: 3
monitor_interface: eth0
public_network: 192.168.0.0/24

Note

Having the ceph_rhcs_version option set to 3 will pull in the latest version of Red Hat Ceph Storage 3.

For additional details, see the all.yml file.

Edit the group_vars/osds.yml file. See the table below for the most common required and optional parameters to uncomment. Note that the table does not include all parameters.

Important

Use a different physical device to install an OSD than the device where the operating system is installed. Sharing the same device between the operating system and OSDs causes performance issues.

Table 3.2. OSD Ansible Settings

Option	Value	Required	Notes
`osd_scenario`	`collocated` to use the same device for write-ahead logging and key/value data (BlueStore) or journal (FileStore) and OSD data `non-collocated` to use a dedicated device, such as SSD or NVMe media to store write-ahead log and key/value data (BlueStore) or journal data (FileStore) `lvm` to use the Logical Volume Manager to store OSD data	Yes	When using `osd_scenario: non-collocated`, `ceph-ansible` expects the variables `devices` and `dedicated_devices` to match. For example, if you specify 10 disks in `devices`, you must specify 10 entries in `dedicated_devices`.
`osd_auto_discovery`	`true` to automatically discover OSDs	Yes if using `osd_scenario: collocated`	Cannot be used when `devices` setting is used
`devices`	List of devices where `ceph data` is stored	Yes to specify the list of devices	Cannot be used when `osd_auto_discovery` setting is used. When using `lvm` as the `osd_scenario` and setting the `devices` option, `ceph-volume lvm batch` mode creates the optimized OSD configuration.
`dedicated_devices`	List of dedicated devices for non-collocated OSDs where `ceph journal` is stored	Yes if `osd_scenario: non-collocated`	Should be nonpartitioned devices
`dmcrypt`	`true` to encrypt OSDs	No	Defaults to `false`
`lvm_volumes`	A list of FileStore or BlueStore dictionaries	Yes if using `osd_scenario: lvm` and storage devices are not defined using `devices`	Each dictionary must contain a `data`, `journal` and `data_vg` keys. Any logical volume or volume group must be the name and not the full path. The `data`, and `journal` keys can be a logical volume (LV) or partition, but do not use one journal for multiple `data` LVs. The `data_vg` key must be the volume group containing the `data` LV. Optionally, the `journal_vg` key can be used to specify the volume group containing the journal LV, if applicable. See the examples below for various supported configurations.
`osds_per_device`	The number of OSDs to create per device.	No	Defaults to `1`
`osd_objectstore`	The Ceph object store type for the OSDs.	No	Defaults to `bluestore`. The other option is `filestore`. Required for upgrades.

The following are examples of the osds.yml file when using the three OSD scenarios: collocated, non-collocated, and lvm. The default OSD object store format is BlueStore, if not specified.

Collocated

osd_objectstore: filestore
osd_scenario: collocated
devices:
  - /dev/sda
  - /dev/sdb

Non-collocated - BlueStore

osd_objectstore: bluestore
osd_scenario: non-collocated
devices:
 - /dev/sda
 - /dev/sdb
 - /dev/sdc
 - /dev/sdd
dedicated_devices:
 - /dev/nvme0n1
 - /dev/nvme0n1
 - /dev/nvme1n1
 - /dev/nvme1n1

This non-collocated example will create four BlueStore OSDs, one per device. In this example, the traditional hard drives (sda, sdb, sdc, sdd) are used for object data, and the solid state drives (SSDs) (/dev/nvme0n1, /dev/nvme1n1) are used for the BlueStore databases and write-ahead logs. This configuration pairs the /dev/sda and /dev/sdb devices with the /dev/nvme0n1 device, and pairs the /dev/sdc and /dev/sdd devices with the /dev/nvme1n1 device.

Non-collocated - FileStore

osd_objectstore: filestore
osd_scenario: non-collocated
devices:
  - /dev/sda
  - /dev/sdb
  - /dev/sdc
  - /dev/sdd
dedicated_devices:
   - /dev/nvme0n1
   - /dev/nvme0n1
   - /dev/nvme1n1
   - /dev/nvme1n1

LVM simple

osd_objectstore: bluestore
osd_scenario: lvm
devices:
  - /dev/sda
  - /dev/sdb

osd_objectstore: bluestore
osd_scenario: lvm
devices:
  - /dev/sda
  - /dev/sdb
  - /dev/nvme0n1

With these simple configurations ceph-ansible uses batch mode (ceph-volume lvm batch) to create the OSDs.

In the first scenario, if the devices are traditional hard drives or SSDs, then one OSD per device is created.

In the second scenario, when there is a mix of traditional hard drives and SSDs, the data is placed on the traditional hard drives (sda, sdb) and the BlueStore database (block.db) is created as large as possible on the SSD (nvme0n1).

LVM advance

osd_objectstore: filestore
osd_scenario: lvm
lvm_volumes:
   - data: data-lv1
     data_vg: vg1
     journal: journal-lv1
     journal_vg: vg2
   - data: data-lv2
     journal: /dev/sda
     data_vg: vg1

osd_objectstore: bluestore
osd_scenario: lvm
lvm_volumes:
  - data: data-lv1
    data_vg: data-vg1
    db: db-lv1
    db_vg: db-vg1
    wal: wal-lv1
    wal_vg: wal-vg1
  - data: data-lv2
    data_vg: data-vg2
    db: db-lv2
    db_vg: db-vg2
    wal: wal-lv2
    wal_vg: wal-vg2

With these advance scenario examples, the volume groups and logical volumes must be created beforehand. They will not be created by ceph-ansible.

Note

If using all NVMe SSDs set the osd_scenario: lvm and osds_per_device: 4 options. For more information, see Configuring OSD Ansible settings for all NVMe Storage for Red Hat Enterprise Linux or Configuring OSD Ansible settings for all NVMe Storage for Ubuntu in the Red Hat Ceph Storage Installation Guides.

For additional details, see the comments in the osds.yml file.

Edit the Ansible inventory file located by default at /etc/ansible/hosts. Remember to comment out example hosts.
1. Add the Monitor nodes under the [mons] section:
```
[mons]
<monitor-host-name>
<monitor-host-name>
<monitor-host-name>
```
2. Add OSD nodes under the [osds] section. If the nodes have sequential naming, consider using a range:
```
[osds]
<osd-host-name[1:10]>
```
  Note
  For OSDs in a new installation, the default object store format is BlueStore.
  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, set the osd_auto_discovery option to true in the osds.yml file.
  Note
  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.
  Optionally, if you want ansible-playbook to create a custom CRUSH hierarchy, specify where you want the OSD hosts to be in the CRUSH map’s hierarchy by using the osd_crush_location parameter. You must specify at least two CRUSH bucket types to specify the location of the OSD, and one bucket type must be host. By default, these include root, datacenter, room, row, pod, pdu, rack, chassis and host.
```
[osds]
<ceph-host-name> osd_crush_location="{ 'root': '<root-bucket>', 'rack': '<rack-bucket>', 'pod': '<pod-bucket>', 'host': '<ceph-host-name>' }"
```
  For example:
```
[osds]
ceph-osd-01 osd_crush_location="{ 'root': 'mon-root', 'rack': 'mon-rack', 'pod': 'monpod', 'host': 'ceph-osd-01' }"
```
3. Add the Ceph Manager (ceph-mgr) nodes under the [mgrs] section. Colocate the Ceph Manager daemon with Monitor nodes.
```
[mgrs]
<monitor-host-name>
<monitor-host-name>
<monitor-host-name>
```
As the Ansible user, ensure that Ansible can reach the Ceph hosts:
```
[user@admin ~]$ ansible all -m ping
```
Add the following line to the /etc/ansible/ansible.cfg file:
```
retry_files_save_path = ~/
```
As root, create the /var/log/ansible/ directory and assign the appropriate permissions for the ansible user:
```
[root@admin ~]# mkdir /var/log/ansible
[root@admin ~]# chown ansible:ansible  /var/log/ansible
[root@admin ~]# chmod 755 /var/log/ansible
```
1. Edit the /usr/share/ceph-ansible/ansible.cfg file, updating the log_path value as follows:
```
log_path = /var/log/ansible/ansible.log
```
As the Ansible user, change to the /usr/share/ceph-ansible/ directory:
```
[user@admin ~]$ cd /usr/share/ceph-ansible/
```

Run the ceph-ansible playbook:

[user@admin ceph-ansible]$ ansible-playbook site.yml

Using the root account on a Monitor node, verify the status of the Ceph cluster:
```
[root@monitor ~]# ceph health
HEALTH_OK
```
Verify the cluster is functioning using rados.
1. From a monitor node, create a test pool with eight placement groups:
  Syntax
```
[root@monitor ~]# ceph osd pool create <pool-name> <pg-number>
```
  Example
```
[root@monitor ~]# ceph osd pool create test 8
```
2. Create a file called hello-world.txt:
  Syntax
```
[root@monitor ~]# vim <file-name>
```
  Example
```
[root@monitor ~]# vim hello-world.txt
```
3. Upload hello-world.txt to the test pool using the object name hello-world:
  Syntax
```
[root@monitor ~]# rados --pool <pool-name> put <object-name> <object-file>
```
  Example
```
[root@monitor ~]# rados --pool test put hello-world hello-world.txt
```
4. Download hello-world from the test pool as file name fetch.txt:
  Syntax
```
[root@monitor ~]# rados --pool <pool-name> get <object-name> <object-file>
```
  Example
```
[root@monitor ~]# rados --pool test get hello-world fetch.txt
```
5. Check the contents of fetch.txt:
```
[root@monitor ~]# cat fetch.txt
```
  The output should be:
```
"Hello World!"
```
  Note
  In addition to verifying the cluster status, you can use the ceph-medic utility to overall diagnose the Ceph Storage Cluster. See the Installing and Using ceph-medic to Diagnose a Ceph Storage Cluster chapter in the Red Hat Ceph Storage 3 Troubleshooting Guide.

3.3. Configuring OSD Ansible settings for all NVMe storage

To optimize performance when using only non-volatile memory express (NVMe) devices for storage, configure four OSDs on each NVMe device. Normally only one OSD is configured per device, which will underutilize the throughput of an NVMe device.

Note

If you mix SSDs and HDDs, then SSDs will be used for either journals or block.db, not OSDs.

Note

In testing, configuring four OSDs on each NVMe device was found to provide optimal performance. It is recommended to set osds_per_device: 4, but it is not required. Other values may provide better performance in your environment.

Prerequisites

Satisfying all software and hardware requirements for a Ceph cluster.

Procedure

Set osd_scenario: lvm and osds_per_device: 4 in group_vars/osds.yml:
```
osd_scenario: lvm
osds_per_device: 4
```

List the NVMe devices under devices:

devices:
  - /dev/nvme0n1
  - /dev/nvme1n1
  - /dev/nvme2n1
  - /dev/nvme3n1

The settings in group_vars/osds.yml will look similar to this example:

osd_scenario: lvm
osds_per_device: 4
devices:
  - /dev/nvme0n1
  - /dev/nvme1n1
  - /dev/nvme2n1
  - /dev/nvme3n1

Note

You must use devices with this configuration, not lvm_volumes. This is because lvm_volumes is generally used with pre-created logical volumes and osds_per_device implies automatic logical volume creation by Ceph.

Additional Resources

3.4. Installing Metadata Servers

Use the Ansible automation application to install a Ceph Metadata Server (MDS). Metadata Server daemons are necessary for deploying a Ceph File System.

Prerequisites

A working Red Hat Ceph Storage cluster.

Procedure

Perform the following steps on the Ansible administration node.

Add a new section [mdss] to the /etc/ansible/hosts file:
```
[mdss]
hostname
hostname
hostname
```
Replace hostname with the host names of the nodes where you want to install the Ceph Metadata Servers.
Navigate to the /usr/share/ceph-ansible directory:
```
[root@admin ~]# cd /usr/share/ceph-ansible
```
Optional. Change the default variables.
1. Create a copy of the group_vars/mdss.yml.sample file named mdss.yml:
```
[root@admin ceph-ansible]# cp group_vars/mdss.yml.sample group_vars/mdss.yml
```
2. Optionally, edit parameters in mdss.yml. See mdss.yml for details.

As the Ansible user, run the Ansible playbook:

[user@admin ceph-ansible]$ ansible-playbook site-docker.yml --limit mdss

After installing Metadata Servers, configure them. For details, see the Configuring Metadata Server Daemons chapter in the Ceph File System Guide for Red Hat Ceph Storage 3.

Additional Resources

The Ceph File System Guide for Red Hat Ceph Storage 3
Understanding the limit option

3.5. Installing the Ceph Client Role

The ceph-ansible utility provides the ceph-client role that copies the Ceph configuration file and the administration keyring to nodes. In addition, you can use this role to create custom pools and clients.

Prerequisites

A running Ceph storage cluster, preferably in the active + clean state.
Perform the tasks listed in Chapter 2, Requirements for Installing Red Hat Ceph Storage.

Procedure

Perform the following tasks on the Ansible administration node.

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.
Navigate to the /usr/share/ceph-ansible directory:
```
[root@admin ~]# cd /usr/share/ceph-ansible
```

Create a new copy of the clients.yml.sample file named clients.yml:

[root@admin ceph-ansible ~]# cp group_vars/clients.yml.sample group_vars/clients.yml

Open the group_vars/clients.yml file, and uncomment the following lines:

keys:
  - { name: client.test, caps: { mon: "allow r", osd: "allow class-read object_prefix rbd_children, allow rwx pool=test" },  mode: "{{ ceph_keyring_permissions }}" }

Replace client.test with the real client name, and add the client key to the client definition line, for example:
```
key: "ADD-KEYRING-HERE=="
```
Now the whole line example would look similar to this:
```
- { name: client.test, key: "AQAin8tUMICVFBAALRHNrV0Z4MXupRw4v9JQ6Q==", caps: { mon: "allow r", osd: "allow class-read object_prefix rbd_children, allow rwx pool=test" },  mode: "{{ ceph_keyring_permissions }}" }
```
Note
The ceph-authtool --gen-print-key command can generate a new client key.

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.

Run the Ansible playbook:

[user@admin ceph-ansible]$ ansible-playbook site.yml --limit clients

Additional Resources

Section 3.8, “Understanding the limit option”

3.6. Installing the Ceph Object Gateway

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.

Prerequisites

A running Red Hat Ceph Storage cluster, preferably in the active + clean state.
On the Ceph Object Gateway node, perform the tasks listed in Chapter 2, Requirements for Installing Red Hat Ceph Storage.

Procedure

Perform the following tasks on the Ansible administration node.

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, use a range, for example:
```
[rgws]
<rgw_host_name_1>
<rgw_host_name_2>
<rgw_host_name[3..10]>
```
Navigate to the Ansible configuration directory:
```
[root@ansible ~]# cd /usr/share/ceph-ansible
```

Create the rgws.yml file from the sample file:

[root@ansible ~]# cp group_vars/rgws.yml.sample group_vars/rgws.yml

Open and edit the group_vars/rgws.yml file. To copy the administrator key to the Ceph Object Gateway node, uncomment the copy_admin_key option:
```
copy_admin_key: true
```
The rgws.yml file may specify a different default port than the default port 7480. For example:
```
ceph_rgw_civetweb_port: 80
```
The all.yml file MUST specify a radosgw_interface. For example:
```
radosgw_interface: eth0
```
Specifying the interface prevents Civetweb from binding to the same IP address as another Civetweb instance when running multiple instances on the same host.
Generally, to change default settings, uncomment the settings in the rgw.yml file, and make changes accordingly. To make additional changes to settings that are not 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, see the Red Hat Ceph Storage 3 Ceph Object Gateway for Production guide. Advanced topics include:
- Configuring Ansible Groups
- Developing Storage Strategies. See the Creating the Root Pool, Creating System Pools, and Creating Data Placement Strategies sections for additional details on how create and configure the pools.
  See Bucket Sharding for configuration details on bucket sharding.
Uncomment the radosgw_interface parameter in the group_vars/all.yml file.
```
radosgw_interface: <interface>
```
Replace:
- <interface> with the interface that the Ceph Object Gateway nodes listen to
For additional details, see the all.yml file.

Run the Ansible playbook:

[user@admin ceph-ansible]$ ansible-playbook site.yml --limit rgws

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 Ubuntu for details on configuring a cluster for multi-site.

Additional Resources

3.6.1. Configuring a multisite Ceph Object Gateway

Ansible will configure the realm, zonegroup, along with the master and secondary zones for a Ceph Object Gateway in a multisite environment.

Prerequisites

Two running Red Hat Ceph Storage clusters.
On the Ceph Object Gateway node, perform the tasks listed in the Requirements for Installing Red Hat Ceph Storage found in the Red Hat Ceph Storage Installation Guide.
Install and configure one Ceph Object Gateway per storage cluster.

Procedure

Do the following steps on Ansible node for the primary storage cluster:

Generate the system keys and capture their output in the multi-site-keys.txt file:

[root@ansible ~]# echo system_access_key: $(cat /dev/urandom | tr -dc 'a-zA-Z0-9' | fold -w 20 | head -n 1) > multi-site-keys.txt
[root@ansible ~]# echo system_secret_key: $(cat /dev/urandom | tr -dc 'a-zA-Z0-9' | fold -w 40 | head -n 1) >> multi-site-keys.txt

Navigate to the Ansible configuration directory, /usr/share/ceph-ansible:
```
[root@ansible ~]# cd /usr/share/ceph-ansible
```
Open and edit the group_vars/all.yml file. Enable multisite support by adding the following options, along with updating the $ZONE_NAME, $ZONE_GROUP_NAME, $REALM_NAME, $ACCESS_KEY, and $SECRET_KEY options accordingly:
```
rgw_multisite: true
rgw_zone: $ZONE_NAME
rgw_zonemaster: true
rgw_zonesecondary: false
rgw_multisite_endpoint_addr: "{{ ansible_fqdn }}"
rgw_zonegroup: $ZONE_GROUP_NAME
rgw_zone_user: zone.user
rgw_realm: $REALM_NAME
system_access_key: $ACCESS_KEY
system_secret_key: $SECRET_KEY
```
Note
The ansible_fqdn domain name must be resolvable from the secondary storage cluster.

Run the Ansible playbook:

[user@ansible ceph-ansible]$ ansible-playbook site.yml --limit rgws

Restart the Ceph Object Gateway daemon:

[root@rgw ~]# systemctl restart ceph-radosgw@rgw.`hostname -s`

Do the following steps on Ansible node for the secondary storage cluster:
1. Navigate to the Ansible configuration directory, /usr/share/ceph-ansible:
```
[root@ansible ~]# cd /usr/share/ceph-ansible
```
2. Open and edit the group_vars/all.yml file. Enable multisite support by adding the following options, along with updating the $ZONE_NAME, $ZONE_GROUP_NAME, $REALM_NAME, $ACCESS_KEY, and $SECRET_KEY options accordingly: The rgw_zone_user, system_access_key, and system_secret_key must be the same value as used in the master zone configuration. The rgw_pullhost option must be the Ceph Object Gateway for the master zone:
```
rgw_multisite: true
rgw_zone: $ZONE_NAME
rgw_zonemaster: false
rgw_zonesecondary: true
rgw_multisite_endpoint_addr: "{{ ansible_fqdn }}"
rgw_zonegroup: $ZONE_GROUP_NAME
rgw_zone_user: zone.user
rgw_realm: $REALM_NAME
system_access_key: $ACCESS_KEY
system_secret_key: $SECRET_KEY
rgw_pull_proto: http
rgw_pull_port: 8080
rgw_pullhost: $MASTER_RGW_NODE_NAME
```
  Note
  The ansible_fqdn domain name must be resolvable from the primary storage cluster.
3. Run the Ansible playbook:
```
[user@ansible ceph-ansible]$ ansible-playbook site.yml --limit rgws
```
After running the Ansible playbook on the master and secondary storage clusters, you will have a running active-active Ceph Object Gateway configuration.
Verify the multisite Ceph Object Gateway configuration:
1. From the Ceph Monitor and Object Gateway nodes at each site, primary and secondary, must be able to curl the other site.
2. Run the radosgw-admin sync status command on both sites.

3.7. Installing the NFS-Ganesha Gateway

The Ceph NFS Ganesha Gateway is an NFS interface built on top of the Ceph Object Gateway to provide applications with a POSIX filesystem interface to the Ceph Object Gateway for migrating files within filesystems to Ceph Object Storage.

Prerequisites

A running Ceph storage cluster, preferably in the active + clean state.
At least one node running a Ceph Object Gateway.
At least one S3 user with an access key and secret.
Perform the Before You Start procedure.

Procedure

Perform the following tasks on the Ansible administration node.

Create the nfss file from the sample file:

[root@ansible ~]# cd /etc/ansible/group_vars
[root@ansible ~]# cp nfss.yml.sample nfss.yml

Add gateway hosts to the /etc/ansible/hosts file under an [nfss] group to identify their group membership to Ansible. If the hosts have sequential naming, use a range. For example:
```
[nfss]
<nfs_host_name_1>
<nfs_host_name_2>
<nfs_host_name[3..10]>
```
Navigate to the Ansible configuration directory, /etc/ansible/:
```
[root@ansible ~]# cd /usr/share/ceph-ansible
```
To copy the administrator key to the Ceph Object Gateway node, uncomment the copy_admin_key setting in the /usr/share/ceph-ansible/group_vars/nfss.yml file:
```
copy_admin_key: true
```

Configure the FSAL (File System Abstraction Layer) sections of the /usr/share/ceph-ansible/group_vars/nfss.yml file. Provide an ID, S3 user ID, S3 access key and secret. For NFSv4, it should look something like this:

###################
# FSAL RGW Config #
###################
#ceph_nfs_rgw_export_id: <replace-w-numeric-export-id>
#ceph_nfs_rgw_pseudo_path: "/"
#ceph_nfs_rgw_protocols: "3,4"
#ceph_nfs_rgw_access_type: "RW"
#ceph_nfs_rgw_user: "cephnfs"
# Note: keys are optional and can be generated, but not on containerized, where
# they must be configered.
#ceph_nfs_rgw_access_key: "<replace-w-access-key>"
#ceph_nfs_rgw_secret_key: "<replace-w-secret-key>"

Run the Ansible playbook:

[user@admin ceph-ansible]$ ansible-playbook site.yml --limit nfss

Additional Resources

3.8. Understanding the `limit` option

This section contains information about the Ansible --limit option.

Ansible supports the --limit option that enables you to use the site, site-docker, and rolling_upgrade Ansible playbooks for a particular section of the inventory file.

$ ansible-playbook site.yml|rolling_upgrade.yml|site-docker.yml --limit osds|rgws|clients|mdss|nfss|iscsigws

For example, to redeploy only OSDs on bare metal, run the following command as the Ansible user:

$ ansible-playbook /usr/share/ceph-ansible/site.yml --limit osds

Important

If you colocate Ceph components on one node, Ansible applies a playbook to all components on the node despite that only one component type was specified with the limit option. For example, if you run the rolling_update playbook with the --limit osds option on a node that contains OSDs and Metadata Servers (MDS), Ansible will upgrade both components, OSDs and MDSs.

3.9. Additional Resources

The Ansible Documentation

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Chapter 3. Deploying Red Hat Ceph Storage

3.1. Prerequisites

3.2. Installing a Red Hat Ceph Storage Cluster

Prerequisites

Procedure

3.3. Configuring OSD Ansible settings for all NVMe storage

3.4. Installing Metadata Servers

3.5. Installing the Ceph Client Role

Prerequisites

Procedure

Additional Resources

3.6. Installing the Ceph Object Gateway

Prerequisites

Procedure

Additional Resources

3.6.1. Configuring a multisite Ceph Object Gateway

3.7. Installing the NFS-Ganesha Gateway

Prerequisites

Procedure

Additional Resources

3.8. Understanding the limit option

3.9. Additional Resources

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3.8. Understanding the `limit` option