Editing Ceph Storage Cluster (section)

==== Mounting a Ceph FS ====
Mounting a ceph filesystem on a system outside the storage cluster requires three things:
# The 'mount.ceph' mount helper, available in the 'ceph-common' package
# The client keyring created on the ceph master node for client authentication
# An entry in the /etc/fstab file

===== Mount Helper =====
All you need is the 'mount.ceph' executable, but there is no way to just get that file.  So, you have to load the ceph common application bundle, which results in a bunch of dependencies that nobody will ever need:

 sudo yum install -y ceph-common

Obviously, you will need to set up the repository as described above depending on your OS ... and specifically the instructions for using the 'updates-testing' repository on Fedora if needed.

===== Client keyring =====
While the admin keyring/credentials could be used, for obvious reasons a separate user should be created for mounting the Ceph FS.  While it is possible to create a separate user for each client system, there is no need to go to that level of paranoia.  The keyring must be created on a system with admin access to the cluster (generally the master node) and then copied to the client system. Go to the master node to create the authentication token, selecting something appropriate for the username:

 ceph fs authorize <filesystem> client.<username> / rw > /etc/ceph/ceph.client.<username>.keyring

This same keyring file can then be copied over to each client system without recreating it.

 ssh <client> mkdir /etc/ceph
 scp /etc/ceph/ceph.conf <client>:/etc/ceph
 scp /etc/ceph/ceph.client.<username>.keyring <client>:/etc/ceph

===== /etc/fstab =====
This line will mount the Ceph FS on boot:

 <master IP>:/                      /<mountpoint>      ceph    name=<username>,_netdev 0 0

At this point, simply mount the filesystem as normal to start using it immediately:

 sudo mount /<mountpoint>