ADSM Server on MVS

Wow!! This subject has generated a lot of comments.  Sounds like we've all
been lulled into a state of acceptance on the network performance for the
MVS server - until someone brought the subject up again .... (was that me
?? - or no, I guess it was Alan).  Just to respond to a few
questions/comments:

     - Yes, we really are only getting 1.5 - 2 GB/hr on the OSA
     - Our network configuration for inbound traffic is through an ATM
router,
       to the ATM switch, the ATM cloud (155 MB/s), and to the OSA.  Again,
ALL
       inbound traffic comes through this route.  I'm not really a network
guru,
       so I can't get much more specific than that.
     - We are running OS/390 2.4, TCP/IP 3.2 (not the rewritten version)
soon to
        be 3.4 (June), which I understand should help the situation.  We do
have
        a socket reserved for ADSM use only.
     - We back up over 300 clients per night, about 75 GB transferred
     - We force compression on at the client
     - We are running 3.1.2.14 of the server
     - We ARE using the MPTHREADING set to YES (not ON). This has
definitely given
        us performance increases in CPU utilization.

Also - Alan, you asked about the processor utilization on the clients.  I'm
afraid I have to admit that I have no idea.  We have, however, always run
scheduled backups on off-hours, and have never really heard any complaints.

                         Ginny





Date:    Tue, 2 Mar 1999 08:10:54 PST
From:    Sam Sheppard <SHS AT SDDPC.SANNET DOT GOV>
Subject: Re: MVS ADSM Server



---------------------------- Top of message ----------------------------
>>--> 03-02-99  08:02  S.SHEPPARD     (SHS)    Re: MVS ADSM Server
>>--> 03-02-99  08:02  S.SHEPPARD     (SHS)    Re: MVS ADSM Server
I would be curious to know what levels of MVS or OS/390 you are running.
We are getting 2-3+G/hr over FDDI when running OS/390 2.5 (the rewritten
TCPIP stack). If you are running anything below this, your performance
will not be that good.  We backup 200+ clients a night with 60-70G
transferred and are not seeing any big problems.
Sam Sheppard
San Diego Data Processing Corp.
shs AT sddpc.sannet DOT gov


Date:    Tue, 2 Mar 1999 16:02:22 +0100
From:    Roger Hohmann <Roger_Hohmann AT WESTLB DOT DE>
Subject: Re: ADSM Server on MVS
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As far as I know, the maximum throughput for ADSM on MVS can be
estimated to 4 MB/sec (which means 14 GB/Hr) with uncompressed data due
to limitations in TCPIP. To break this bareer you have to use another
network connection, another tcpip stack and another adsm server address
space. In fact, we are reaching something between 2.5-3.5 MB/s. If
anyone has better performance with uncompressed data, please tell.
Maybe the new OS/390 2.7 performs better.
60 GB/hr means ~16 MB/sec which sounds unreachable with a single FDDI
Connection, maybe the newly announced Gigabit Ethernet OSA for S390 may
fit. You may think about a dedicated ADSM Server on this machine.
The improvement with client compression varies from nothing (compressed
tar's, zips) to a factor of 5 in our environment. Depending on the
data, we are calculating 1.5-2.5. But - there have been some problems
with compression (which are solved, as far as I know).
Regards
Roger


Date:    Tue, 2 Mar 1999 09:53:12 -0500
From:    Tjeerd Saijoen <tsaijoen AT BFSORG DOT COM>
Subject: Re: MVS ADSM Server
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IBM is working on a better TCP/IP stack I believe it is released already
but
I am not sure of that. Also use the MPTHREADING parameter (set this to ON).
Regards Tj

Date:    Tue, 2 Mar 1999 07:46:33 -0600
From:    Nathan King <nathan.king AT USAA DOT COM>
Subject: Re: MVS ADSM Server
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We're also in this scenario. ADSM MVS (Open Edition) with ATM backbone and
again rarely see over 1.5 - 2Gb/hr on backups, the only exception is in the
case of large flat files such as database dumps where we have seen it go as
high as 4Gb an hour! wow! We have a very small Risc/6000 server
(Uniprocessor w/512Mbyte Ram) on the same ATM backbone which peforms about
6
times better!!!
We know that there are defnitely a lot of issues with TCP/IP performance on
MVS. We backup over 1,000 clients each night to 5 ADSM Servers spread
throughout the sysplex and frequently get lost client tcp/ip sessions
during
the course of the night and generally poor performance. TCP/IP on MVS just
plain stinks. I've lost count of the fixtests, ptfs and hipers that have
been applied to both TCP/IP and ADSM in an attempt to get around these
problems. IBM really seem to be chasing their own tail on this one and I
don't expect TCP/IP on MVS to improve for some time.
One thing we did do which helped a lot was reserving the appropriate tcp/ip
sockets on MVS for use exclusively by ADSM. This did provide a lot more
stability. Perhaps you've been smart enough to do this already. The even
smarter thing to do would be to migrate off MVS to AIX / NT.
Regards,
Nathan



Hi Virginia,
we are also locking at ATM for our S/390 Server.
Do you really get only 1.5 -2 GB per Hour??
We get 1 to 1.7 GB/Hour already on a 16 MB Tokenring (If everthing works
well).
I would expect ATM to give at least 20 GB/Hour.
Have I missed something or what kind of OSA do you have?
___________________________________________________
Kind Regards
Andreas Buser
Tel: ++41 61 285 73 21  Fax: ++41 61 285 90 27
Email: Andreas.Buser AT Basler DOT ch