We never have enough resources.

The 4-LTO drives in one library, are shared amongst 3-TSM servers which
transfer over 2TB, nightly.  The 4th TSM server is dedicated to Domino
backups, which use it's 4-LTO and 4-3592 drives, 24x7, transferring almost
3TB of mostly non-compressable data (I never get more than 800GB on a
3592-2 tape) daily.

With the drives being busy almost nonstop, this leaves little time for
things like reclamation, etc.  Right now, I had to manually bring back
150-offsite LTO tapes with less than 20% utilization, since I don't have
time/drives to perform standard offsite reclamation by rebuilding them
from the primary onsite tapes.

It is a constant, hand-management juggling act, having to constantly
intercede when the regular schedules get out-of-whack due to bursts in new
data, LTO drives failing, etc.

One of the servers is going to grow by 150GB or more of new data
(radiological images), daily.

So, trying to add one more TSM server to try to share 4-6 drives, just
won't work.



"Allen S. Rout" <asr AT UFL DOT EDU>
Sent by: "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
01/11/2007 10:04 AM
Please respond to
"ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>


To
ADSM-L AT VM.MARIST DOT EDU
cc

Subject
Re: [ADSM-L] Recommendations for hardware replacement/upgrade






>> On Wed, 10 Jan 2007 12:08:22 -0500, Zoltan Forray/AC/VCU
<zforray AT VCU DOT EDU> said:


> Thanks for the feedback.

> Yes, I realize you can't beat AIX for I/O bandwidth.  Unfortunately,
> it comes down to $$$$$$ (doesn't it, always).

I think your $/performance-unit is much better on AIX than it will be
in intel-land.  I call the x86 option cheap now, pricey later.  But
you've already said that AIX isn't on the table.

> I agree it would be beneficial to break things up. However, this
> would lead to even more contention for resources (tape, tape
> libraries) than we already have.  We have enough issues juggling
> 4-TSM servers against 3-tape libraries (1-3494 2-3583).

I don't understand how you concluded this.  Whatever the count of
servers you're using, the drive use should be related to the client
node count and behavior, and should not be varying too much.  Am I
missing something?

> I hadn't really thought about running multiple TSM server instances
> on one machine.  Not sure if it is worth the effort/risk!

If you are already running multiple TSM servers, you've got the
coordination infrastructure in place already.  (or you don't in which
case God Bless You) That won't be much different if you've got 2
servers on one box.  I'm running 11 on one box now: Having relatively
small databases makes a huge improvement in reliablity.


- Allen S. Rout