OK, I'll bite. We don't use the TDB client, we use home grown
scripts that use the standard TSM archive client, but I believe the
bottleneck in your case was the same as mine.

        The bottleneck in your scenario is the 100Mb Ethernet interface. In
our testing, we find that a TSM session can sustain a throughput of about 11
MB/sec (which equates to about 88 Mb/sec). That is about 88% data and the
TCP/IP overhead. That's about as good as it gets, from my understanding.

        Doing the math on that figure, (11MB/sec X 60sec X 60min)=
40GB/hour. It looks like a 350GB database would be able to move in about
8.75 hours. Obviously, with the compression on the client turned on, you are
actually moving less data over the wire and are achieving a better
throughput at 6 hours for your backup.

        So, if you have one 100Mb interface on your SAP client, you can
start multiple client sessions and you probably still won't see any
improvement because the card is maxed out.

        We were up against the same wall and ended up putting GB Ethernet
cards (and switches, etc) on both the TSM server and select clients. The
improvement in speeds were anywhere from 2X to 4X depending on the client.
On some overtaxed clients, it moved the bottleneck to their slower disks or
CPU. In a few cases, the 3590E drives became the bottleneck, but we just put
the 'resourceutilization' to a higher value to multi-thread the client to
multiple tape drives. Not sure how you multi-thread the TSM for SAP agent,
but I believe it is possible.

        Hope that helps.

Ben Bullock
UNIX Systems Manager
Micron Technology Inc

> -----Original Message-----
> From: Francisco Molero [mailto:fmolero AT YAHOO DOT COM]
> Sent: Tuesday, March 20, 2001 8:35 AM
> To: ADSM-L AT VM.MARIST DOT EDU
> Subject: SAP and 3494 performance.
>
>
> Hello,
> I have a query about performance between a TDP for SAP
> R/3 under HP-UX and TSM Server with a 3494 library.
> The size of database is 350 GB and the connection is
> via tcpip (ethernet 100). I used the brbackup -c -t
> offline command and the bacukp is sent to tape pool in
> the library 3494. I have a private network and also I
> am using the compression parameter to yes in the
> client in order to improve the performance in the
> network. The backup takes 6 hours in backing up the db
> and this time is very high. I need to reduce it. the
> drives are 3590, and the format device class is DRIVE.
> Can someone help me about the parameters which can
> improve this performance ???
>
> Regards,
> Fran
>
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