[Lustre-devel] changelog interface

[Nathaniel Rutman]

Peter, early in the changelog arch we had designed the changelog user 
API as a series of files that would show up under a special .lustre 
directory.  After the ZFS changelog investigation, I think it makes more 
sense to try and match the ZFS API so that changes to user tools are 
minimized.

So, as "zfs diff snap1 snap2" produces a stream to stdout, I think we 
should make "lctl diff startrec [endrec]" produce a similar stream.  We 
would also need a "lctl purge endrec" to clear out old changelog records.

Any objections?