Command 13: OST_STATFS
~~~~~~~~~~~~~~~~~~~~~~
[[ost-statfs-rpc]]

OST_STATFS ('pb_opc' = 13) is an RPC that queries data about the
underlying file system for a given OST. It's form and use are nearly
identical to the MDS_STATFS RPC. Refer to <<mds-statfs-rpc>> for
details. The only differences in OST_STATFS are that it has a distinct
'pb_opc' value, it carries information about an OST (instead of an
MDT), and it can be generated in this one additional way:  There is a
regularly scheduled process that 'pings' each OST from each MDT using
OST_STATFS, so that the MDT can remain current on the available space
on the OSTs.