When the "ceph nfs cluster create" command was first implemented, documentation was scarce. We got the command working by trial-and-error.
Recently, "sesdev create ses7" started to fail like this:
master: ++ ceph nfs cluster create sesdev_nfs node3
master: Error EINVAL: Invalid export type: sesdev_nfs
master: +++ err_report 791
master: +++ local hn
master: +++ set +x
master: Error in provisioner script trapped!
Nowaday's the syntax is:
$ ceph nfs cluster create <type> <clusterid> [<placement>]
where
<type> signifies the export type, which corresponds to the NFS Ganesha file system
abstraction layer (FSAL). Permissible values are “cephfs” or “rgw”, but currently only
“cephfs” is supported.
Source: https://docs.ceph.com/en/octopus/cephfs/fs-nfs-exports/#create-nfs-ganesha-cluster