On Tuesday 16 January 2001 21:57, you wrote:
> I'm nearly ready to activate DRM on a new server, but I have a worry about
> copypools for disk storage.  One of the diskpools is for smaller servers
> which migrate to a limited number of collocated tapes.  This pool is not
> yet very active, so there are many nodes which have not yet migrated off to
> tape.  I have the time and resources to copy my diskpools to tape daily,
> but I wonder what sort of confusion I may be generating.
>
> For instance, what happens to cached files that are on tape as well as
> disk?  Do I get two copies? or only the one that already exists from the
> backup of the tape?

No, from a logical standpoint, each file exists only twice: The "original" in
the primary storage pool, and a copy in the corresponding copy pool. A user
does not have to care about the underlying storage media. The cached files
are only another "pointer" for the file in the primary storage pool.

> What happens to a file that migrates to tape some time
> after a copy is made from disk?  does it supercede the previous copy? or
> are there again two copies in the copypool?

A file migrated from tape is the same file in the primary storage pool, and
therfore it will not be copied again if a copy already exists.

> What happens in case of
> disaster requiring a restore storage operation?  At this point, I really
> don't know what to expect

>
> All assistance will be gratefully accepted.


---
Joerg Nouvertne
Joerg Nouvertne

.. who will leave the good old ADSM area shortly to take the new adventure
TSM.