On 12 Feb 2002 at 21:14, Kelly Lipp wrote, in part:
> I  believe the key to long term storage is the notion of data
> refreshment on the tapes.  With reclamation, we get that.  If archive
> data is mixed with backup data we get reclamation due to backup
> retention policies being much less (typically) than archive.  Some will
> argue that moving this data around isn't efficient, but if ensuring that
> data can be read is the goal, moving it around occasionally is
> important.

I agree that long term storage is an interesting problem, but I don't
see reclamation (alone) as solving it. It may not be efficient, but it
isn't sufficient!  ;-)   For example, I believe I put my current drives
into production about 2 years ago.   3% (about 60) of my tapes are
"full" and haven't been mounted since 2000!  Reclamation has caused
most data to move, but not all.

If one believes long term storage is important and moving data around
important to achieving success, then reclamation is not sufficient.

*SM doesn't automate mandated movement of data on it's storage, but it
enables it, since it is trivial to write SQL to find "old" tapes (so
one might run MOVE DATA on them).  Moving data from "old" tapes allows
one to rebuild from another (hopefully still "good") copy, should a
failure occur.

cheers, wayne


Wayne T. Smith                          ADSM AT Maine DOT edu
ADSM Technical Coordinator - UNET       University of Maine System