Re: ADSM across ATM

1997-12-19 13:00:38
Subject: Re: ADSM across ATM
From: "Michael J. Drees" <drees AT BERBEE DOT COM>
Date: Fri, 19 Dec 1997 12:00:38 -0600

I'm seeing about the same throughput of 5 Mb/s per stream backing up
Oracle databases on 8-way SMP's (SP2) direct to a 3494 library with 3590
I'm actually able to achieve greater throughput (8Mb/s and higher)
when increasing the TCPwindowsize setting to greater than 1024K.
The SCSI connection to the the tape drives seems to be the current
bottleneck.  Also, the larger TCPwindowsize also caused socket
connection errors.

Over the token ring network backing up Novell and NT servers we see about
900K - 1.2Mb/s.

Is anyone else out there seeing better throughput on an SP?  If so, what
settings are you using for ADSM and (no -a) options.

> From: Kauffman, Tom <KauffmanT AT NIBCO DOT COM>
> From: Kauffman, Tom <KauffmanT AT NIBCO DOT COM>
> Subject: Re: ADSM across ATM
> Date: Friday, December 19, 1997 8:41 AM
> 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).
> Tom Kauffman
> Senior Technical Analyst
> NIBCO, Inc
> >----------
> >From:  Jeff Renicker[SMTP:jrenicker AT VNET.IBM DOT COM]
> >Sent:  Thursday, December 18, 1997 9:42 AM
> >Subject:       ADSM across ATM
> >
> >>Hello,
> >>
> >>Try sending the data directly to Tape.  You can expect a throughput of
> >>anywhere
> >>between 17G-22G an hour.  Yes as high as
> >>22Gig an hour.  You'll have to tune your ATM network but these numbers
> >>are
> >>right.
> >>
> >>Enjoy!
> >>
> >>Francois
> >
> >It appears that you have your ATM network tuned for ADSM backups.  Have
> >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
> >NFS
> >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).
> >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
> >backups will the tiny SAP transactions suffer in performance?
> >
> >I'd really appreciate any information you can share.
> >
> >Thanx!
> >Jeff Renicker
> >
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