Thanks for the response Gerd,

We're running backint 2.2.5.1....
In the .utl file we also have..."MULTIPLEXING            4 "
But we get the following in the sap backup log....

BR229I Calling backup utility...
BR278I Command output of '/usr/sap/FLD/SYS/exe/run/backint -u FLD -f backup
-i /
oracle/FLD/sapbackup/.bcxuqrkj.lst -t file_online -p
oracle/FLD/sapbackup/.bcxuqrkj.lst -t file_online -p
/oracle/FLD/dbs/initFLD.utl
 -c':
BKI2012I: Multiplexing is not supported in 'util_file_online' mode.
BKI2012I: Multiplexing is not supported in 'util_file_online' mode.

                   BACKINT/ADSTAR Distributed Storage Manager

  Interface between SAPDBA Utilities and IBM ADSTAR Distributed Storage
Manager
                 - Version 2, Release 2, Level 5.1 for AIX -

the .sap file gives the "backup device type" choices of ....
[tape | tape_auto | pipe | pipe_auto | disk | util_file | util_file_online]

..and we're using the util_file_online which appears to be the reason why we
cannot do multiplexing.
The ability to multiplex would be nice ..tis a pity. 
We are making use of the RL_COMPRESSION option...performance tests
with/without showed it was
worthwhile.

regards,
Andrew.

> -----Original Message-----
> From: Gerd Kehrer [SMTP:kehrer AT DE.IBM DOT COM]
> Sent: Thursday, 16 July 1998 19:45
> To:   ADSM-L AT VM.MARIST DOT EDU
> Subject:      Re: ADSM disk read performance ?
> 
> 
> Andrew,
> 
> what version of BACKINT/ADSM do you use ?
> Beginning from BACKINT/ADSM 2.2.5.1 you can use MULTIPLEXING to merge the
> data from different disks to one datastream which is then send to one tape
> drive.
> This code also supports the RL_COMPRESSION parameter which controlls a
> very
> lightweight compression algorithm to compress the data on the client side.
> 
> 
> Mit freundlichen Grüßen / Best Regards
> Gerd Kehrer
> 
> 
> IBM Deutschland Entwicklung GmbH
> Schoenaicherstrasse 220
> Dept. 3293/7103-05
> D-71032 Boeblingen
> Germany
> 
> Web: http://www.ibm.de/ide/esd.html
> Hotline: (+49) (0)7031 16 2277
> Fax: (+49) (0)7031 16 3619
> EMail: backint AT de.ibm DOT com
> 
> 
> 
> ADSM-L AT VM.MARIST DOT EDU on 07/16/98 06:29:16 AM
> Please respond to ADSM-L AT VM.MARIST DOT EDU
> To: ADSM-L AT VM.MARIST DOT EDU
> cc:
> Subject: ADSM disk read performance ?
> 
> 
> Hello,
> 
> Does anyone have any tips on maximising the ADSM's READ performance from
> disk, when
> transferring data direct to a single tape drive (no disk pool on this
> particular system)
> 
> We're running ADSM Client 3.1.20.3 on AIX 4.3.1, to ADSM server 3.1.1.3
> (server runs AIX 4.3.0).
> Disk is Ultra SCSI.
> We're using ADSM to perform an online backup of a SAP Oracle database
> (using
> brbackup with backint)
> Using a blocksize of 128k gives us the best read performance from a dd
> test.
> 
> In the init<SID>.utl we've included:
> DISKBUFFSIZE    131072
> ADSMBUFFSIZE    131072
> 
> WITHOUT the use of more tape drive, or disk pools, what else can be done
> to
> maximise throughput ?
> (drive is a DLT7000)
> 
> Andrew Swift
> Unix Systems Consultant
> Retail Technology Services
> Coles Myer Limited
> *andrew.swift AT colesmyer.com DOT au
> *61 (3) 9483 7629
> 
>