On the wishlist item:

I have heard talk about implementing an automatic multi-stream restore
similar to what we have now with backup and resourceutilization.  This will
be slick but then only really slick if one uses collocate=filespace.  I
believe it will still provide better restore times since it will know what
tape volumes client data is on and will mount multiple volumes.  If one
thinks about this for a few minutes, one realizes the whole thing is damn
complicated.  Also, it would appear that collocation would not be a good
thing if you use this technique: you want data on multiple tapes.

TSM restore is fairly smart.  Before data is sent, TSM has optimized data
coming off each volume.  It does not back hitch to get data: it processes
serially through the tape.  I don't know the algorithm for determining which
tape it uses first.  I would guess perhaps the tape that has the most data
(based on number of files, not size) and do that one first but that's just a
guess.

As for the new functionality I would guess at an implementation that orders
the restore by number of files on volumes and choose the n largest volumes,
where n is resourceutilization or the number of filespaces, mount those
tapes and start that number of restores.  Then, since there might be data
for a filespace on one of the other tapes that mounted, get the data for the
other filespace off that tape too.  So work the n tapes until all the data
for all n filespaces are off the tapes and then mount another batch.

If I were a programmer this would be a fun exercise.  No, I'm not looking
for a job.  I learned it's a lot easier to talk about sexy code than it is
to write it!

Kelly J. Lipp
Storage Solutions Specialists, Inc.
PO Box 51313
Colorado Springs, CO 80949
lipp AT storsol DOT com or kelly.lipp AT storserver DOT com
www.storsol.com or www.storserver.com
(719)531-5926
Fax: (240)539-7175