Jim,
How do I UNSUBSCRIBE?
Please help, I'm getting inundated and can't do my primary work.
Thanks in advance,
DouG

> -----Original Message-----
> From: Geuther, Jim [SMTP:Geuther.Jim AT PMINTL DOT CH]
> Sent: Wednesday, May 27, 1998 9:58 AM
> To:   ADSM-L AT VM.MARIST DOT EDU
> Subject:      Re: Performance Issues
>
> Monitor the SSA-disks being backed up, you should be happy if you can
> read > 6MB/s out of a single disk-drive. So the single-disk-drive
> throughput is the bottleneck. To improve throughput try with with
> multiple sessions.
>
>
>         -----Original Message-----
>         From:   Matthew Emmerton [SMTP:Matthew_Emmerton AT AGORAINC DOT NET]
>         Sent:   Wednesday, May 27, 1998 2:19 PM
>         To:     ADSM-L AT VM.MARIST DOT EDU
>         Subject:        Performance Issues
>
>         We're running ADSM 3.1 on an RS/6000 R50 server (4x604e) with
> ~150 GB of
>         SSA DASD, of which ~60 GB is being backed up daily.  We're using
> a 3590
>         drive as our backup device.  Oh, and it has 2 GB of RAM.
>
>
>         These are some older statistics (when we were backing up
> less...)
>
>         Total number of bytes transferred:  36.02 GB
>         Data transfer time:                 5,616.98 sec
>         Network data transfer rate:         6,724.53 KB/sec
>         Aggregate data transfer rate:       1,348.57 KB/sec
>
>         How I am interpreting this is that over the network (TCP/IP,
> 100BaseT
>         Ethernet) I'm getting ~6.5 MB/s (around 65% utilization) which
> is
>         acceptable.  However, the aggregate (as I'm interpreting it)
> would be the
>         overall throughput of the system.  Now, according to the 3590
>         documentation, it should be able to back up at up to 9 MB/s.
> The SCSI-2
>         bus driving the 3590 can handle at least SCSI-1 speeds of 10
> MB/s.   The
>         SSA driving our DASD can handle well over SCSI-2 speeds; so the
> drive and
>         network I/O don't seem to be the limiting factor.
>
>         What I'm wondering if there is not enough iron behind the ADSM
> server,
>         which is causing the performance problem - that is, why we can
> only back up
>         1.3 MB/s when all of the subsystems can handle more.  We've
> tried all kinds
>         of performance optimizations on our TCP/IP settings, as well as
> using over
>         512 MB of RAM for ADSM cache, with minimal performance
> improvement.  We've
>         tried the stuff in the ADSM Performance Tuning Guide (v3) and
> the folks
>         from IBM don't seem to have any clear-cut answers.
>
>         What I'd like to know is if a) anyone else has had similar types
> of
>         performance problems and b) what is a decent typical backup
> speed?  Am I
>         being too ambitious in wanting ~9MB/s?
>
>         --
>         Matthew Emmerton, System Administration
>         Agora Food Merchants, National IT
>         +1 (905) 565-4231