Angel,

If you think about what's going on during a restore like this, locality of
reference within the database is going to be very low since files arrive for
a client at varying times.  Therefore, the effectiveness of the cache is not
surprising.  This is a tough query.  Not knowing the exact layout of the
database we can't guess how tough.  I guess I'm not surprised that the
server works very hard on something like this.  What was the outcome?  How
long did it take to restore the file system?  How many tape mounts?  Bottom
line: did the restore meet your service level agreements?

We did some testing a month or so ago restoring a large file system.  Due to
circumstances beyond our control, it never completed, i.e., someone kept
killing our restore!  During the test, though, we were able to move ~14 GB
consisting of a nearly a million itsy bitsy files in a little over three
hours.  Sun Solaris Server (big honking system, I might add), 3494 with 6
3590 drives.  I didn't track how many tape mounts, but I'm guessing 10-15.
We didn't monitor the performance of the system during this, but we were
doing other stuff on it and it didn't seem bothered by the restore going on.

Having never tried a large restore like this, I was pleased.  The test
indicated we would be able to perform this sort of restore within our SLA.

Kelly J. Lipp
Storage Solutions Specialists, Inc.
PO Box 51313
Colorado Springs CO 80949
719-531-5926
www.storsol.com
lipp AT storsol DOT com