In message " ADSM Experiences", ADSM-L AT VM.MARIST DOT edu writes:
>
>Forgive my obtuseness but, it appears that the performance problem is then
>the rate at which data is delivered to your disk storage pool?  The 500-
>1000Kb/s is for a single machine (session) or for several at once?
>

This is for several concurrent sessions. Generally we are seeing maximum
performance at aroung 4-6 concurrent sessions, after that performance begins
to go down.

>Have you considered that the problem may be with the clients ability to
>transmit data rather than the server?
>

Client performance is definitely a problems, which IBM says they will be
addressing sometime next year. But we should be able to overcome client
bottlenecks by increasing the number of concurrent sessions.

>I'm use to seeing average data transfer rates of 250-500Kb/s from
>a number of clients with client compression enabled, and the compression
>does slow the average transfer rate quite a bit.  My DEC Unix Alpha
>workstation running a migrated version of the Ultrix client does manage
>to get better than 1500Kb/s (even with compression) all by its self.
>A quick run while I typed this did a rate of 1613Kb/s while 3 other
>machines are running as well.  Now all this is going to a VM server but,
>I would find it hard to believe that I'm getting better performance from
>an old single CPU 9121 w/4.5MB channels and dasds without caching or
>dasdfw on thickwire ethernet than you would be from your RS/6000 and FDDI.
>Heck 25% of the CPU is just TCPIP trying to keep up with all the traffic
>being generated by ADSM (and I've learned from this exactly why IBM makes
>TCPIP offload solutions for VM :).
>

Actually, from the replies I have seen so far, ADSM seems better tuned for
the VM systems than for the RS/6000 systems. File size has a tremendous
impact on performance. What is the average file size on the Ultrix, how did
you get that performance number? On large files we see clients push 700-800
Kb/s which is the maximum of ethernet on the client.

>---
>Keith A. Crabb         Keith AT UH DOT EDU
>University of Houston  Operating Systems Specialist +1-713-743-1530
>