It is done magically.  :-)     well not really.

Reclamation of a tape from an offsite pool when not present is done by
referencing the same data that's onsite. (can you say: know-it-all DB?)

So reclaming an offsite tape X is done by copying the data that is still
valid on X from each of the onsite tapes that holds copies of files that
are on X,  one at a time, onto a new offsite tape.

For me I find its best done by reclaming 20-40 offsite tapes at the same
time over a 48 hour period (weekend) because it reads virtually every
onsite tape in the library. Fortunately TSM is smart enough to only read
each onsite tape once during this process.  Just don't change rec in the
middle.

 I have a perl program that guess-timates how much reclamation can be
tolerated over the weekend and sets the rec appropriately.

... joe.f.


Joseph A Faracchio,  Systems Programmer, UC Berkeley
Private mail on any topic should be directed to :
         joef AT socrates.berkeley DOT edu
 (510)642-7638 (w)  (209)483-JOEF (M)
                             5633


On Mon, 19 Nov 2001, Marc Levitan wrote:

> What is the benefit of using reclamation on the offsite copy tape pool?
> How is this possible if the tapes are offsite?
> Expiration makes sense, but reclamation?
>
>
> Marc Levitan
> Storage Manager
> PFPC Global Fund Services
>