HPSS configuration for GCMDC2

[dave zimmerman <dmzimmerman@lbl.gov>]

This morning I met with John Riordan to discuss the GC Hpss
configuration and  the tape situation.
I learned that it is possible to lock a tape so that no more files will
be written to it.  This facility can be used to maximize the number of
tapes available to the GC by transferring say 10 1-Gig files to a single
tape, locking it and
moving on to the next tape for the next 10 gig of data.  After the
GCMDC2 data sinking period is over we would unlock the tapes so that
they would be available to be filled out.

If this seems reasonable Id like to follow this plan.

Regarding the HPSS configuration for MDC2 the proposed configuration is:

File purging policy:
Do not purge any file which has been accessed in the last 5 minutes
Start purge when the cache is 5% full.
Stop purge when the cache is empty.

Tape drive allocation:
5 drives will be available to the StarReco
a maximum of 3 of those drives will be available for file migration.

Deferred dismount will be on.  That is, a tape will not be dismounted
from a drive unless there is a request to mount a new tape in that
drive.