Hi all,

I am running into a strange performance issue at a small TSM site.
They have an new intel based TSM server running Windows 2008 R2 running TSM
5.5 (don't ask) with enough CPU and memory to run the server 4 times over.
It has 2 disks in raid 1 for the TSM log, 4 disks in raid 10 for the TSM
database and 5 disks (all 10k) for the diskpool in raid 5.
The server has 2 1Gb/s ethernet ports in a 2Gb/s LACP channel.

A normal CIFS copy to the server raid 5 filesystem loads the interface up
to 25%.
A TSM backup to LTO (I believe LTO4) loads the interface up to about the
same load.
However a TSM backup to the diskpool only get the load up to 5-6%.
I have tried a default dsmserv.opt and dsm.opt and 'tuned' ones.
Multiple clients or just one, MSSQL or fileserver data, nothing matters, as
soon as I go to the diskpool the performance is gone.

Even a local backup to 127.0.0.1 is slow to the diskpool but fast to tape.
I did filesystem checks, recreated the filesystem, swapped the
raidcontroller (that was done before performance checks and seems a bit
silly now) but I can't find the issue.
There are no errors in Windows or TSM, everything is just fine but very
very slow.
I recreated the diskpool volumes one by one to make sure there is no weird
fragmentation going on, that didn't change anything, even with a single
1Gb/s connection the speed is still many times faster to tape than it is to
the diskpool but a filecopy via CIFS to the same disk is fast.

Has anybody ever seen this before?

Regards,
   Stefan