DB2 V7 to V8 - Unable to allocate bufferpool

Ravikumar Devireddy

DB2 V7 to V8 - Unable to allocate bufferpool
Esteemed listers,

DB2 V8 FP5 ( 32BIT ) , AIX 5.2

We recently migrated from DB2 V7 to DB2 v8 fp5. After
mingration to V8 we are unable to use the bufferpool
with the size that we had in V7.
We had to decrease the bufferpool size to get the
instance/DB working.

Earlier in V7 we had about 1.4GB bufferpool, now we
are not able to increase the size of this beyond
400MB..!

db2 "alter bufferpool IBMDEFAULTBP SIZE 200000"
SQL20189W The buffer pool operation (CREATE/ALTER)
will not take effect until
the next database startup due to insufficient memory.
SQLSTATE=01657

Thats about 1GB less than what we had in V7.

Any idea what the problem is here ? i have
crosschecked all the db shared mem settings with V7
and current V8..no changes.
The only changes between V8 and V7 were some
maxagents, poolagents.

Any ideas please..

Thanks.

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Kenneth Swinski

Re: DB2 V7 to V8 - Unable to allocate bufferpool
(in response to Ravikumar Devireddy)
We had a similar problem with one of our databases. With our db cfg, we had a 1.25 Gb limit for database shared memory. Here's how it's calculated:
db shared memory ..
(bufferpools + dbheap + utilheap + pkgcache + sheapthres_shr if INTRA_PARALLEL enabled + locklist) + approx 10% overhead

After we changed our db cfg and bufferpools to fit within 1.25 Gb, we got the same message you did about the bufferpool creation being deferred. I suspect memory was somehow fragmented because when we recycled the instance, the bufferpool did get created. We're planning on converting this instance to 64-bit soon so we can have bigger bufferpools.

Here's an excellent artice from Developer Works on The DB2 UDB memory model:

http://www-128.ibm.com/developerworks/db2/library/techarticle/dm-0406qi/index.html



-----Original Message-----
From: DB2 Data Base Discussion List [mailto:[login to unmask email]On
Behalf Of Ravi Reddy
Sent: Tuesday, December 14, 2004 5:01 PM
To: [login to unmask email]
Subject: DB2 V7 to V8 - Unable to allocate bufferpool


Esteemed listers,

DB2 V8 FP5 ( 32BIT ) , AIX 5.2

We recently migrated from DB2 V7 to DB2 v8 fp5. After
mingration to V8 we are unable to use the bufferpool
with the size that we had in V7.
We had to decrease the bufferpool size to get the
instance/DB working.

Earlier in V7 we had about 1.4GB bufferpool, now we
are not able to increase the size of this beyond
400MB..!

db2 "alter bufferpool IBMDEFAULTBP SIZE 200000"
SQL20189W The buffer pool operation (CREATE/ALTER)
will not take effect until
the next database startup due to insufficient memory.
SQLSTATE=01657

Thats about 1GB less than what we had in V7.

Any idea what the problem is here ? i have
crosschecked all the db shared mem settings with V7
and current V8..no changes.
The only changes between V8 and V7 were some
maxagents, poolagents.

Any ideas please..

Thanks.

__________________________________________________
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around
http://mail.yahoo.com

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