Cleanup of slave PFSes

[Matthew Dillon]

:Greetings,
:
:I have trouble understanding how daily cleanup jobs interact with slave 
:PFSes being updated with
:hammer mirror-stream.

    It is a bit confusing and could use some work.  I think the hammer
    cleanup directive currently only scans mounted PFS's, so if the PFS
    is not mounted it winds up not getting cleaned up.

    hammer cleanup can be called manually with a path to the PFS the cleanup
    is desired on.  Typically that would be a "<mountpt>/pfs/<pfsname>" path.
    The PFS does not have to be mounted in that case.

    I consider this a bug actually.  The hammer cleanup command should iterate
    through available PFS's and clean them up whether they are mounted or
    not.  The feature was added before slave PFS's were really operational
    so the assumption was that all the PFS's would be null-mounted.  But
    slave PFS's are not usually null-mounted (because null-mounting a slave
    PFS will basically just mount the current snapshot of it and not track
    changes made to it after the mount).

    The easiest work-around is to create a cron job which runs once or twice
    a day which does 'hammer cleanup <path_to_pfs>'.

						-Matt