doc/cephfs: mention new options for "fs volume create" cmd

Command "ceph fs volume create" accepts 2 new options to allow users to
pass data and metadata pool name. Update docs to include mention of both
the options.

Signed-off-by: Rishabh Dave <[email protected]>

Author: rishabh-d-dave

doc/cephfs/fs-volumes.rst

@@ -44,11 +44,14 @@ Create a volume by running the following command:
 
 .. prompt:: bash #
 
-   ceph fs volume create <vol_name> [placement]
-
-This creates a CephFS file system and its data and metadata pools. This command
-can also deploy MDS daemons for the filesystem using a Ceph Manager orchestrator
-module (for example Rook). See :doc:`/mgr/orchestrator`.
+   ceph fs volume create <vol_name> [placement] [--data-pool <data-pool-name>] [--meta-pool <metadata-pool-name>]
+
+This creates a CephFS file system and its data and metadata pools. Alternately,
+if the data pool and/or metadata pool needed for creating a CephFS volume
+already exist, these pool names can be passed to this command so that the
+volume is created using these existing pools. This command can also deploy MDS
+daemons for the filesystem using a Ceph Manager orchestrator module (for
+example Rook). See :doc:`/mgr/orchestrator`.
 
 ``<vol_name>`` is the volume name (an arbitrary string). ``[placement]`` is an
 optional string that specifies the :ref:`orchestrator-cli-placement-spec` for

doc/cephfs/multifs.rst

@@ -29,6 +29,12 @@ support the new file system. The deployment technology used, e.g. cephadm, will
 also configure the MDS affinity (see: :ref:`mds-join-fs`) of new MDS daemons to
 operate the new file system.
 
+If the data and metadata pools for the volume are already present, the names of
+these pool(s) can be passed as follows::
+
+    ceph fs volume create <vol-name> --meta-pool <meta-pool-name> --data-pool <data-pool-name>
+
+
 
 Securing access
 ---------------