?

For a long time I have believed (fairly sure originally told by IBM)
that the method is to increase the buffpool size untill cache hit goes
over 99%

Talking to a colleague, we really don't see how reducing bufpool size
can increase the cache hit%

Can anyone explain what we are missing?

Thanks,

Matt.

_-'-_
  -|-


-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of
Joni Moyer
Sent: Thursday, January 20, 2005 2:51 PM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Re: Cache Hit % below 99%

Hello!

I just wanted to thank everyone for suggestions and help with this
matter!
I changed the bufpoolsize to 419430, which is 10% of the physical
memory,
and then reset the bufpool and now my cache hit % is 100%.  At this
point,
until I see otherwise, I am going to conclude that I had the bufpoolsize
setting too high at 524288.  I will continue to monitor the cache hit %
of
the database, but I believe the problem to be solved.  Thank you again!

********************************
Joni Moyer
Highmark
Storage Systems
Work:(717)302-6603
Fax:(717)302-5974
joni.moyer AT highmark DOT com
********************************



             "Curtis Stewart"
             <Curtis.Stewart@L
             AWSON.COM>
To
             Sent by: "ADSM:           ADSM-L AT VM.MARIST DOT EDU
             Dist Stor
cc
             Manager"
             <[email protected]
Subject
             .EDU>                     Re: Cache Hit % below 99%


             01/20/2005 09:33
             AM


             Please respond to
             "ADSM: Dist Stor
                 Manager"
             <[email protected]
                   .EDU>






What is your buffpool setting? Run "query option" and look for the
buffpoolsize. Look in the dsmserv.opt file and read the comments about
this parameter, then look in the server manual for this too.

curtis.stewart AT lawson DOT com



Joni Moyer <joni.moyer AT HIGHMARK DOT COM>
Sent by: "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
01/20/2005 07:19 AM
Please respond to
"ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>


To
ADSM-L AT VM.MARIST DOT EDU
cc

Subject
Cache Hit % below 99%






Hello All!

I have noticed that the cache hit % is below 99%.  This is a newly
defined
TSM 5.2.2.5 server on an AIX 5.2 OS.  Are there any special
parameters/definitions that could contribute to the percentage being so
low?  Thanks!

         Available Space (MB): 24,576
        Assigned Capacity (MB): 19,484
        Maximum Extension (MB): 5,092
        Maximum Reduction (MB): 15,000
             Page Size (bytes): 4,096
            Total Usable Pages: 4,987,904
                    Used Pages: 45,207
                      Pct Util: 0.9
                 Max. Pct Util: 0.9
              Physical Volumes: 3
             Buffer Pool Pages: 131,072
         Total Buffer Requests: 132,692
                Cache Hit Pct.: 95.15
               Cache Wait Pct.: 0.00
           Backup in Progress?: No
    Type of Backup In Progress:
  Incrementals Since Last Full: 0
Changed Since Last Backup (MB): 0.73
            Percentage Changed: 0.41

********************************
Joni Moyer
Highmark
Storage Systems
Work:(717)302-6603
Fax:(717)302-5974
joni.moyer AT highmark DOT com
********************************


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