From: Jonathan Williams (jonathw@shubertorg.com)
Date: Tue Oct 08 2002 - 16:01:11 EDT
Ok...let me give a tad bit of background before getting to my question.
I have a machine here (ES40, Tru64 5.1 patch 3)that is setup exactly like our
production machines, except for the fact that it is designed as a stand-alone
system (part of our warm disaster recovery site), so it is not part of the SAN.
On our production machines, the tape libraries (TL895) goto a FCTC II and then
in turn to a 16-port fibre switch, and all the systems are connected to this
switch as well. This other stand-alone machine has only a single local tape
drive (TZ89--just like the ones inside the tape library).
Now, the problem I am seeing is related to Informix, which I know is not
"Tru64-centric", but I'm hoping there is a Tru64 answer. The problem I'm seeing
is that this stand-alone system takes literally about TWICE as long to restore
an informix database as any of our production machines. I know it's not the
tape (same tape is used to restore the database on all systems). Once it
finishes everything is fine...there are no errors reported by Informix or Tru64,
it just takes an unusually long time.
So I decided to compare this ES40 system with an identical (cpu, ram, etc) ES40
production machine. I did a series of vdumps and vrestores and kept track of
times and things like that. It turned out very inconclusive: the stand-alone
machine consistently took longer than the production machine to vdump, but the
production machine was consistently slower with the vrestores.
So anyway...I want to do some more testing to come to the bottom of this
problem...but I'm wondering if there is anything in the operating system that
would let me look at real-time I/O of the tape drive, and the disks out on the
SAN. I want to compare the stand-alone to a production machine and see if I can
track down where the hold-up is. I'm sure there are wonderful 3rd party
programs I can purchase for this, but I was hoping for a quick simple built-in
tool that I'm just not aware of. Any and all help will be appreciated as usual.
Jonathan Williams
Unix Systems Administrator
The Shubert Organization, Inc.
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