RE: Balancing Disk Data Across Arms

["Shaw, David" <dshaw@xxxxxxxxxxx>]

Tom,

I used it at my previous employer.  It didn't cause any problems, and appeared
to work as advertised.  I don't know how much it will help you - it might be
worth your while to upgrade to V4R4 and take advantage of its much more advanced
capabilities in this regard.

Dave Shaw
Spartan International, Inc.
Spartanburg, SC

-----Original Message-----
From: Law, Tom [mailto:actlaw@nmhg.com]
        
Has anyone used the DSKBAL command provided by IBM on a 4.2 system?
This function is available via PTF.

We run some accounting Monthend jobs that are heavy I/O.  When these
jobs run, other batch jobs slow down (other batch jobs are actively
running) and show I/O waits in  Performance Tools.

In the past year, we have added several disk drives to this system.
Generally, 1 or 2 at a time.  I believe what has happened is that since
these drives are empty when they are added, the IBM algorithm for
spreading data across arms actually fills these empty drives until the
percentage used is even again across all arms.  Thus, restoring or
copying files in production applications actually put this data on
these empty drives.  (timing)    I can see in performance tools that
during the Monthend process, 4 or 5 arms will exceed the guidelines for
the device.  These are the where the accounting data is located.

Without doing a full SAVSYS and RESTORE (option 21),  The Support Center
told me to install this PTF and use the DSKBAL command.  
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