Hello,
We are doing the best we can acting as our own DB2 on AIX LPARs DBAs without any formal training.
In order to isolate two databases, and keep them completely seperate, we are running two distinct copies of DB2 on a single LPAR (guest instance of AIX 5.3). Currently we have STMM running, with Instance_memory and Database_memoery set to automatic.
Is this a desireable configuration? I am concerned that the two copies of DB2 might be in conflict when it comes to acquiring memory. I was considering the idea of setting the Database_memory for one or both copies to a fixed value.
The LPAR is configured with 20 gig. It appears that each copy of DB2 is vying for 18 gig. I beleive I can add more memory. Running each copy in its own LPAR is not a option.

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On Oct 6, 12:32*pm, CW Burfle <cwbur... (AT) aol (DOT) com> wrote:
Hey,

I think setting the INSTANCE_MEMORY limit is more appropriate in your
situation, because this is at the border you've already drawn yourself
(ie. 2 instances).

--
Frederik

"CW Burfle" <cwburfle (AT) aol (DOT) com> wrote

If you are going to use STMM, I would suggest that you get the latest
fixpack available, which is 9.5.6a or 9.7.3.

I believe we have two discrete copies of DB2 running, each with their own filesystems, and configuration settings. Each one contains only one database instance. Wouldn't we want to set the Database_memory on each copy?
I am under the impression that Database_memory would cap the amoount of host memory that each copy would use.

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"CW Burfle" <cwburfle (AT) aol (DOT) com> wrote

You probable need a lesson in DB2 architecture. On a single server, you can
have one or more DB2 instances and each instance can have zero or many
databases. Each instance is separate, but STMM is supposed to be able to
share memory between them automatically (when it works correctly).

The number of copies of DB2 on /opt/ibm/db2 directory (this is for Linux,
not sure what it is for AIX) has no bearing on whether the DB2 instances are
separate. There is no reason to have separate copies of the code if they are
the same version, so long as you create separate DB2 instances.

The instance memory setting caps the amount of memory a single instance can
use, and the database memory caps the amount of shared memory that a
database can use within that instance. Note that private memory for
connections are at the instance level and not part of shared database
memory.

Thanks to Frederick for his response.
We are going to set instance_memory to a fixed value for each copy of DB2 running on this LPAR

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