Your awesome Ceph clusters will find themselves increasingly full of user data. It will be necessary to track and anticipate utilization over time to plan future cluster expansion. It's important to plan ahead: acquiring and provisioning new servers can take months. Your users will be doubly unhappy if the cluster runs out of space before you can expand. Ceph provides tools that show the overall cluster utilization as well as the distribution per Ceph pool. We will use the df subcommand of the ceph utility to display the current stats.
root@ceph-client0:~# ceph dfGLOBAL:SIZE AVAIL RAW USED %RAW USED65333M 63376M 1957M 3.00POOLS:NAME ID USED %USED MAX AVAIL OBJECTSrbd 0 0 0 21113M 0cephfs_data 1 0 0 21113M 0cephfs_metadata ...