Migrate the Ceph back end¶

Ceph uses FileStore or BlueStore as a storage back end. You can migrate the Ceph storage back end from FileStore to BlueStore and vice versa using the Ceph - backend migration pipeline.

To migrate the Ceph back end:

1. In your project repository, open the cluster/ceph/osd.yml file for editing:

   1. Change the back end type and block_db or journal for every OSD disk device.
   2. Specify the size of the journal or block_db device if it resides on another device than the storage device. The device storage will be divided equally by the number of OSDs using it.

   Example:

   parameters:
     ceph:
       osd:
         bluestore_block_db_size: 10073741824
   #      journal_size: 10000
         backend:
   #        filestore:
           bluestore:
             disks:
             - dev: /dev/sdh
               block_db: /dev/sdj
   #            journal: /dev/sdj
   

   Where the commented lines are the example lines that must be replaced and removed if migrating from FileStore to BlueStore.

2. Log in to the Jenkins web UI.

3. Open the Ceph - backend migration pipeline.

4. Specify the following parameters:

   Parameter	Description and values
   SALT_MASTER_CREDENTIALS	The Salt Master credentials to use for connection, defaults to salt.
   SALT_MASTER_URL	The Salt Master node host URL with the salt-api port, defaults to the jenkins_salt_api_url parameter. For example, http://172.18.170.27:6969.
   ADMIN_HOST	Add cmn01* as the Ceph cluster node with the admin keyring.
   TARGET	Add the Salt target name of the Ceph OSD node(s). For example, osd005* to migrate on one OSD HOST or osd* to migrate on all OSD hosts.
   OSD	Add * to target all OSD disks on all TARGET OSD hosts or comma-separated list of Ceph OSDs if targeting just one OSD host by TARGET For example 1,2.
   WAIT_FOR_HEALTHY	Verify that this parameter is selected as it enables the Ceph health check within the pipeline.
   PER_OSD_CONTROL	Select to verify the Ceph status after migration of each OSD disk.
   PER_OSD_HOST_CONTROL	Select to verify the Ceph status after the whole OSD host migration.
   CLUSTER_FLAGS	Add a comma-separated list of flags to apply for the migration procedure. Tested with blank.
   ORIGIN_BACKEND	Specify the Ceph back end before migration.

   Note

   The PER_OSD_CONTROL and PER_OSD_HOST_CONTROL options provide granular control during the migration to verify each OSD disk after its migration. You can decide to continue or abort.

5. Click Deploy.

The Ceph - upgrade pipeline workflow:

1. Set back-end migration flags.
2. Perform the following for each targeted OSD disk:
   1. Mark the Ceph OSD as out.
   2. Stop the Ceph OSD service.
   3. Remove the Ceph OSD authentication key.
   4. Remove the Ceph OSD from the Ceph cluster
   5. Remove block_db, block_wal, or journal of the OSD.
3. Run the ceph.osd state to deploy the OSD with a desired back end.
4. Unset the back-end migration flags.