Tim,
We run ADSM/6000 as follows. Our config is not as big as what you have now,
in certain respects.
Server:
RS/6000 41T
64M memory
2 SCSI channels
9 GB disks (currently). Trying to get to 25GB, but having problems with
Seagate Barracuda 4GB drives.
1 GB AIX, ADSM software, utilities, 2 log volume copies
4 GB ADSM DB (duplexed 2GB)
2 GB backup disk storage
.5 GB archive disk storage
the rest is currently not utilized
LAGO Datawheel (2 Exabyte 8500C 8mm tape drives)
DB and logvols are duplexed on different SCSI channels
Make sure you have at least 2 copies of each DB vol and log vol.
250 clients
100 GB managed storage
2-3 GB transferred per night (runs from 12:30 to about 4)
I have not done an analysis to see how much data we could theoretically
transfer per night.
Suggestions
Use faster disk. We are using SCSI-2. We seem to be bottlenecked on
disk I/O, I think to the database. I'd go with either F/W SCSI-2 or
something even faster if you can afford it.
A fast processor will help, especially for Migrations, Reclaims, Expirations,
etc. The 41T we got has a 601 processor in it, which was considered pretty
fast when we got it.
Get something with lots of expansion slots. The 41T has 4, which I think
is pretty good (for the price). Spread your data on multiple scsi busses
to avoid bus contention during backup.
Spread your database across multiple volumes. You will be bottlenecked on
seek time to your database, probably. Spreading out should help this.
Pay attention to your AIX error log (e.g., 'errpt' command). This will
show you if you have disks about to fail, or if you are running out of
memory buffers (mbufs). You may need to tune the AIX networking parms.
We are in the process of doing this now.
We are headed towards putting FDDI on our server, which may or may not
improve performance. Once we get past our disk bottleneck (hopefully by
spreading the DB across our new disks), I think FDDI will help us.
If you can afford it, steer clear of 4/8mm technology. Go with 3x90 or
DLT. Our experience has been with 8mm, and it requires lots of vigilance.
I've seen others on this list talk about much larger RS/6000 configurations,
with 900-level models. I don't know how much they buy you, other than a
nice cabinet to put your disks into. I think the processors and the
channels have similar performance characteristics.
Good luck.
..Paul
Paul Zarnowski Phone: 607/255-4757
Cornell Information Technologies Fax: 607/255-6523
Cornell University US Mail: 315 CCC, Ithaca, NY 14853-2601
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On Thu, 14 Sep 1995 12:18:00 EDT PITTSON, TIMOTHY said:
On Thu, 14 Sep 1995 12:18:00 EDT PITTSON, TIMOTHY said:
>Hi all,
> We're in the process of outsourcing our mainframe and I need to get
>ADSM moved...
>the most logical platform choice is AIX. I was wondering if anybody has had
>any experience with
>this (i.e. sizing the RS/6000, disk configuration, amount of memory, etc.)
> Our current ADSM environment is a version 1.2 server (service level 14)
>running on a 3090-500J, MVS/ESA 4.3, about 100 clients (mostly servers with
>a handful of workstations), a 4 GB database, 6 GB backup disk pool, 1 GB
>archive disk pool, We're backing up between 8-14 GB a night (most clients
>use compression). We're using up to 14 hours of CPU time a day on a
>3090-500J. (Actually we're using more since we have 2 ADSM servers, one for
>onsite and one for offsite backups.. the 14 hours of CPU time is what's used
>by our onsite server... I hope to be able to get away with 1 ADSM version
>2.1 server on AIX).
> Any experiences / suggestions would be most appreciated.
>
>Regards...
>Tim Pittson
>pittson1 AT bwmail1.hcc DOT com
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