On Feb 16, 2005, at 3:13 AM, Mark Strasheim wrote:

at the moment i let the library build a backupset, where "a" equals 1
in "a" week. This process takes about 6 hours to complete ... which is
way to long. The set is from one server only and about 20GB. I quess
that the scsi Library is to blame for that, but of cause i may be
wrong.
The Library is a IBM 4560SLX, TSM-Server 5.2.5 .
If anybody as an idea how to get this process a bit fast, where a bit
equals 6 hours for about 120GB.

Building a Backup Set is much the same as performing a full restore of
all Active files, with most of the same considerations for improving
speed. (See ADSM QuickFacts topic "Restoral performance" for general
tips.) Collocation and commensurate reclamation are big factors here:
mounting many input tapes always prolongs the process. Also, some tape
technologies can be painfully slow in repositioning: for example, APAR
IC33920 cites poor Locate performance on LTO Ultrium such that a Read
will be done instead of a Locate to position to where the next file to
be restored is a few tape blocks away. See also Technote 1142185,
"Improving TSM Restore Performance From Tape".

This kind of situation brings home the lesson we all have to heed about
preparing for the ultimate goal of a backup system: restoral. Too
often, the emphasis is on backup, with efforts going to optimize that
daily nuisance task to get it out of the way faster. But then comes the
rude awakening when a department manager gets steamed when recovery of
their failed-disk file system is taking all day.

   Richard Sims