5 The 'ost_id' identifies a single object on a particular OST.
20 The 'ost_id' structure contains an identifier for a single OST object.
21 The 'oi' structure holds the OST object identifier as used with Lustre
22 1.8 and earlier, where the 'oi_seq' field is typically zero, and the
23 'oi_id' field is an integer identifying an object on a particular
24 OST (which is identified separately). Since Lustre 2.5 it is possible
25 for OST objects to also be identified with a unique FID that identifies
26 both the OST on which it resides as well as the object identifier itself.