At 10:26 AM 4/26/2009, Nick Laflamme wrote:

On Apr 26, 2009, at 9:03 AM, Remco Post wrote:

On Apr 26, 2009, at 12:10 , Peter Buschman wrote:

Apologies if this is a well-known question but I am scratching my
head trying to answer it.

Basically, what I want to know is if a migration job in TSM job will
also migrate expired data on the volumes it is migrating.  In a
sense, I am wondering if part of the effect of reclamation can be
achieved through initiating migration to another storage pool.

If data is migrated from one storage pool to another, do the volumes
in the new storage pool still contain expired files that were in the
first storage pool after the migration?

Expired data is not in the TSM database any more, so it can't be
migrated.

Without contradicting Remco's point, I'll add that the MOVE DATA
command includes an optional parameter, RECONSTRUCT, that would
influence the recovery of space used by files expired from an
aggregate of data. This option may occasionally trigger some confusion
about when space used by expired files is recovered during copy
procedures.

If I am not mistaken, migration does not reconstruct aggregates, but rather
moves them in their entirety.  Thus, expired data contained within an
aggregate with other active data will be migrated to tape.  I believe the
only processes that re-aggregate data are RECLAIM and MOVE DATA (when the
RECONSTRUCT=YES option is specified).

Files that are not aggregated with others (i.e., standalone) would not get
migrated, of course.

..Paul



--
Paul Zarnowski                            Ph: 607-255-4757
Manager, Storage Services                 Fx: 607-255-8521
719 Rhodes Hall, Ithaca, NY 14853-3801    Em: psz1 AT cornell DOT edu