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.
+MDT). The MDT may send regular OST_STATFS RPCs to each OST in order
+to keep its information about free space and utilization updated.
+That allows the MDS to make more optimal file allocation decisions.