Lustre File IDs
^^^^^^^^^^^^^^^
[[file-id]]

Each resource stored on a target is assigned an identifier that is
unique to that resource.

----
struct lu_fid {
	__u64 f_seq;
	__u32 f_oid;
	__u32 f_ver;
};
----

The 'f_seq' field identifies the target. That is, all the resources
with a common 'f_seq' will be on the same target. A target can have
more than one 'f_seq' value assigned to it.

The 'f_oid' gives the specific value for a given resource that is
unique to that resource on that target.

The 'f_ver' value identifies which version of a resource is being
identified, in the event that the resource is being updated, and
different hosts might be referring to different versions of the same
resource.