Jeff, the killer on 100Mb ethernet will be the small ethernet mtu. We've
run data direct to tape over the SP switch and get about 5 MB/sec per
tape unit (my peak so far has been 39 GB/hr of SAP Oracle database to
three tape units). Using the 100Mb ethernet, I get closer to 2.7 MB/sec
per tape unit and I haven't been able to drive any given 100Mb card over
42-45Mb (three concurrent sessions, same ADSM server and tape units, an
8-way SMP system as the client -- just like the over-the-switch config,
but a free-standing J30).
Senior Technical Analyst
>From: Jeff Renicker[SMTP:jrenicker AT VNET.IBM DOT COM]
>Sent: Thursday, December 18, 1997 9:42 AM
>To: ADSM-L AT VM.MARIST DOT EDU
>Subject: ADSM across ATM
>>Try sending the data directly to Tape. You can expect a throughput of
>>between 17G-22G an hour. Yes as high as
>>22Gig an hour. You'll have to tune your ATM network but these numbers
>It appears that you have your ATM network tuned for ADSM backups. Have you
>also used it for non-ADSM traffic? If so, is the performance good?
>We have an SP2 with an SP (TB3) switch and currently run our ADSM backups,
>mounts, and SAP R/3 transactions across it. We are considering installing a
>dedicated network to use as a backup for the switch (in case it fails). We
>are looking at ATM, FDDI, and 100Mb ethernet. We are intrigued by your
>numbers and are wondering if we install ATM and tune it for large file ADSM
>backups will the tiny SAP transactions suffer in performance?
>I'd really appreciate any information you can share.