CephFS Exports over NFS

CephFS namespaces can be exported over NFS protocol using the NFS-Ganesha NFS server.

Requirements

  • Latest Ceph file system with mgr enabled

  • ‘nfs-ganesha’, ‘nfs-ganesha-ceph’, ‘nfs-ganesha-rados-grace’ and ‘nfs-ganesha-rados-urls’ packages (version 3.3 and above)

Create NFS Ganesha Cluster

$ ceph nfs cluster create <type> <clusterid> [<placement>]

This creates a common recovery pool for all NFS Ganesha daemons, new user based on cluster_id, and a common NFS Ganesha config RADOS object.

NOTE: Since this command also brings up NFS Ganesha daemons using a ceph-mgr orchestrator module (see Orchestrator CLI) such as “mgr/cephadm”, at least one such module must be enabled for it to work.

<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.

<clusterid> is an arbitrary string by which this NFS Ganesha cluster will be known.

<placement> is an optional string signifying which hosts should have NFS Ganesha daemon containers running on them and, optionally, the total number of NFS Ganesha daemons the cluster (should you want to have more than one NFS Ganesha daemon running per node). For example, the following placement string means “deploy NFS Ganesha daemons on nodes host1 and host2 (one daemon per host):

“host1,host2”

and this placement specification says to deploy two NFS Ganesha daemons each on nodes host1 and host2 (for a total of four NFS Ganesha daemons in the cluster):

“4 host1,host2”

For more details on placement specification refer to the orchestrator doc but keep in mind that specifying the placement via a YAML file is not supported.

Update NFS Ganesha Cluster

$ ceph nfs cluster update <clusterid> <placement>

This updates the deployed cluster according to the placement value.

Delete NFS Ganesha Cluster

$ ceph nfs cluster delete <clusterid>

This deletes the deployed cluster.

List NFS Ganesha Cluster

$ ceph nfs cluster ls

This lists deployed clusters.

Show NFS Ganesha Cluster Information

$ ceph nfs cluster info [<clusterid>]

This displays ip and port of deployed cluster.

Set Customized NFS Ganesha Configuration

$ ceph nfs cluster config set <clusterid> -i <config_file>

With this the nfs cluster will use the specified config and it will have precedence over default config blocks.

Reset NFS Ganesha Configuration

$ ceph nfs cluster config reset <clusterid>

This removes the user defined configuration.

Create CephFS Export

$ ceph nfs export create cephfs <fsname> <clusterid> <binding> [--readonly] [--path=/path/in/cephfs]

This creates export RADOS objects containing the export block, where

fsname is the name of the FS volume used by the NFS Ganesha cluster that will serve this export.

clusterid is the NFS Ganesha cluster ID.

binding is the pseudo root path (must be an absolute path).

Delete CephFS Export

$ ceph nfs export delete <clusterid> <binding>

This deletes an export in an NFS Ganesha cluster, where:

clusterid is the NFS Ganesha cluster ID.

binding is the pseudo root path (must be an absolute path).

List CephFS Exports

$ ceph nfs export ls <clusterid> [--detailed]

It lists exports for a cluster, where:

clusterid is the NFS Ganesha cluster ID.

With the --detailed option enabled it shows entire export block.

Get CephFS Export

$ ceph nfs export get <clusterid> <binding>

This displays export block for a cluster based on pseudo root name (binding), where:

clusterid is the NFS Ganesha cluster ID.

binding is the pseudo root path (must be an absolute path).

Configuring NFS Ganesha to export CephFS with vstart

  1. Using cephadm

    $ MDS=1 MON=1 OSD=3 NFS=1 ../src/vstart.sh -n -d --cephadm
    

    This will deploy a single NFS Ganesha daemon using vstart.sh, where:

    The daemon will listen on the default NFS Ganesha port.

  2. Using test orchestrator

    $ MDS=1 MON=1 OSD=3 NFS=1 ../src/vstart.sh -n -d
    

    This will deploy multiple NFS Ganesha daemons, each listening on a random port, where:

    NFS is the number of NFS Ganesha clusters to be created.

    NOTE: NFS Ganesha packages must be pre-installed for this to work.

Mount

After the exports are successfully created and NFS Ganesha daemons are no longer in grace period. The exports can be mounted by

$ mount -t nfs -o port=<ganesha-port> <ganesha-host-name>:<ganesha-pseudo-path> <mount-point>

Note

Only NFS v4.0+ is supported.