Chapter 2. Preparing overcloud nodes

Procedure

1. Create the following pools in your Ceph Storage cluster, relevant to your environment:

   • Storage for OpenStack Block Storage (cinder):

     [root@ceph ~]# ceph osd pool create volumes <pgnum>

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   • Storage for OpenStack Image Storage (glance):

     [root@ceph ~]# ceph osd pool create images <pgnum>

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   • Storage for instances:

     [root@ceph ~]# ceph osd pool create vms <pgnum>

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   • Storage for OpenStack Block Storage Backup (cinder-backup):

     [root@ceph ~]# ceph osd pool create backups <pgnum>

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   • Optional: Storage for OpenStack Telemetry Metrics (gnocchi):

     [root@ceph ~]# ceph osd pool create metrics <pgnum>

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     Use this storage option only if metrics are enabled through OpenStack. If your overcloud deploys OpenStack Telemetry Metrics with CephFS, create CephFS data and metadata pools.

2. If your overcloud deploys the Shared File Systems service (manila) with Red Hat Ceph 4 (Ceph package 14) or earlier, create CephFS data and metadata pools:

   [root@ceph ~]# ceph osd pool create manila_data <pgnum>
   [root@ceph ~]# ceph osd pool create manila_metadata <pgnum>

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   Replace <pgnum> with the number of placement groups. Red Hat recommends approximately 100 placement groups per OSD in the cluster, divided by the number of replicas (osd pool default size). For example, if there are 10 OSDs, and the cluster has the osd pool default size set to 3, use 333 placement groups. You can also use the Ceph Placement Groups (PGs) per Pool Calculator to determine a suitable value.

3. If your overcloud deploys the Shared File Systems service (manila) with Red Hat Ceph 5 (Ceph package 16) or later, you do not need to create data and metadata pools for CephFS. You can create a filesystem volume. For more information, see Management of MDS service using the Ceph Orchestrator in the Red Hat Ceph Storage Operations Guide.

4. Create a client.openstack user in your Ceph cluster with the following capabilities:

   • cap_mgr: allow *
   • cap_mon: profile rbd

   • cap_osd: profile rbd pool=volumes, profile rbd pool=vms, profile rbd pool=images, profile rbd pool=backups,

     [root@ceph ~]# ceph auth add client.openstack mgr allow * mon profile rbd osd profile rbd pool=volumes, profile rbd pool=vms, profile rbd pool=images, profile rbd pool=backups

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5. Note the Ceph client key created for the client.openstack user:

   [root@ceph ~]# ceph auth list
   ...
   [client.openstack]
   	key = <AQC+vYNXgDAgAhAAc8UoYt+OTz5uhV7ItLdwUw==>
   	caps mgr = allow *
   	caps mon = profile rbd
   	caps osd = profile rbd pool=volumes, profile rbd pool=vms, profile rbd pool=images, profile rbd pool=backups
   ...

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   The key value in the example, AQC+vYNXgDAgAhAAc8UoYt+OTz5uhV7ItLdwUw==, is your Ceph client key.

6. If your overcloud deploys the Shared File Systems service with CephFS, create the client.manila user in your Ceph Storage cluster with the following capabilities:

   • cap_mds: allow *
   • cap_mgr: allow *
   • cap_mon: allow r, allow command "auth del", allow command "auth caps", allow command "auth get", allow command "auth get-or-create"`

   • cap_osd: allow rw

     [root@ceph ~]# ceph auth add client.manila mon allow r, allow command "auth del", allow command "auth caps", allow command "auth get", allow command "auth get-or-create"' osd 'allow rw' mds 'allow *' mgr 'allow *'

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7. Note the manila client name and the key value to use in overcloud deployment templates:

   [root@ceph ~]# ceph auth get-key client.manila
        <AQDQ991cAAAAABAA0aXFrTnjH9aO39P0iVvYyg==>

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8. Note the file system ID of your Ceph Storage cluster. This value is specified in the fsid field, under the [global] section of the configuration file for your cluster:

   [global]
   fsid = <4b5c8c0a-ff60-454b-a1b4-9747aa737d19>
   ...

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