Hi Joe,

At 03:39 PM 2/28/2002 -0500, you wrote:
>Environment:
>Server: 4.1.3.0
>Platform: S390
>
>1.  Logmode: We're going to change the Logmode from Normal to Roll Forward.  
>What determines the amount of disk I'll require?

You need enough log space to hold all the db changes between scheduled db 
backups.  So it depends
on how much activity you have and when you want db backups to occur.  You 
should also set the
dbbackuptrigger as a safety valve; it will kick off a dbb when the log gets nn% 
full.  I am on s/390 also;
I set the trigger up to direct incremental dbb's to sms managed disk.  My log 
is 7,146 megs; if you upgrade
the server code 4.2.(1.9) you can make the log more than 5.3GB, up to 13GB.

You can do a 'q log f=d' and monitor the cumulative consumption value to see 
how much you
need for a day or between scheduled db backups.

>2.  Bufpoolsize: We're going to increase from 24576K to ?.  What's the 
>determining factor?

Monitor the cache hit % in 'q db f=d'.  The rule of thumb is to get it up to 
98%.  My bufpoolsize is
262144k.  You can dynamically changes this with the setopt command.


>3.  Mpthreading:  We're going to turn it on.  Are there any considerations I 
>should concern myself with?

Can't say much about mpthreading; my processor has only 1 engine, but tivoli 
recommended it
anyway, so I turned it on.

>None of this info is in the manual that I'm aware of.  I get a log of "try 
>this" form Tivoli support.  Unfortunately, I don't work in an environment 
>where I can "try this" without first knowing what
>the repercussions are.
>
>
>Regards,
>Joe Wholey
>TGA Distributed Data Services
>Merrill Lynch
>Phone: 212-647-3018
>Page:  888-637-7450
>E-mail: joseph_wholey AT ml DOT com

----------
Bill Colwell
Bill Colwell
C. S. Draper Lab
Cambridge Ma.