Even though the files are on the same node as the server, you ARE
     using external network.  PFT 13 introduced two enhancements which
     should help:
      1. Commmethod sharedmem which utilizes a different tcp port and
     utilizes shared memory segments (cross-memory services for mvs fans).
     2. Pthreads support which allows adsm threads to have differing
     priorities .


______________________________ Reply Separator _________________________________
Subject: Q: ADSM Backup Performance @ 200kB/s !
Author:  "A. Vrtala -- Vienna Univ. Computing Center"
<Aron.Vrtala AT CC.UNIVIE.AC DOT AT> at ~Internet
Date:    8/26/97 1:48 PM


Hi ADSM'ers !

A question about ADSM performance during backup:

We are running an IBM 7015/R40 4CPU System with 512 MB Memory using 12 SSA
disks (model 3401 with 4.5 GB capacity) (except for the OS) on one SSA bus
under AIX 4.2+ (Server: 2.1.5.12, Client: 2.1.0.6). All disks are mirrored. The
database has currently a size of about 3.5 GB (ie. 64% usage) and the staging
area is on a separate mirror. For sake of completeness: Tapestorage is built by
an IBM 3494 with IBM 3590 Tapes. A copy of a large file between mirrored disks
in AIX yields a transfer-rate of 16 MB/s in average, while ADSM is in action.
This is fine. Typically our CPU's are busy up to 30%, however we experience
relatively high CPU IO-waits (no other job can be scheduled for computation and
CPU's seem to be fast enough).

Here comes the problem:
An ADSM backup of a relatively quiet area _within_ the same machine (no
external network involved) results in an average transfer rate of
about:      200 kB/s  !!

This is an unacceptably low rate for having a copy of data between disks
with adding/changing just some records to the database effectively.
Our backup performance of other clients using TCP/IP network yields 100kB/s
typically.

Is there anyone out there, who could give us an idea of what may be ill
configured ??!
I'd suggest that answers are sent directly to   aron.vrtala AT univie.ac DOT at
and - at the end - I'll post a summary.

Thanks in advance, Aron
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Aron Vrtala                           | Internet eMail:
Aron Vrtala                           | Internet eMail:
   Vienna University Computer Center  |          vrtala AT cc.univie.ac DOT at
   Dept. of Decentral Systems         |          aron.vrtala AT univie.ac DOT at
   RA-Physik, Boltzmanngasse 5        |
   A-1090 Vienna                      | Tel:     +43-1-313 67/3061
   Austria, Europe                    | Fax:     +43-1-310 26 83
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