Question Re: About DB2 Automatic Storage Management in Technology Q&A

About DB2 Automatic Storage Management

Former Member — Tue, 17 Jun 2008 09:22:32 GMT

Does it mean that DB2 will create/resize containers of table spaces automatically if we use Automatic Storage Management to manage?

If yes, when DB2 will create new container within a table space?

If yes, when DB2 will resize containers within a table space?

Please advise. thanks so much.

James

Re: About DB2 Automatic Storage Management

Former Member — Tue, 17 Jun 2008 10:48:23 GMT

Hi James,

yes, with Automatic Storage DB2 will manage the containers. Some details:

- if more space is required in a tablespace, the containers of the last stripe set are increased.

- DB2 creates as many containers as storage paths are available

- If you add a new storage path, the new storage path does not get used immediately. It only get accessed if another storage path runs full or a new tablespace gets created.

- DB2 does not free up space automatically. In DB2 8 and 9 there is no possibility to decrease the tablespace. In DB2 9.5 you can use ALTER TABLESPACE ... REDUCE

Regards, Jens

Re: About DB2 Automatic Storage Management

Former Member — Tue, 17 Jun 2008 12:07:38 GMT

Thanks for you reply, I still have some questions.

Q1: When the size of table space need to be increased, by default, which one will occur, (1)DB2 will increase the size of existing container, or (2)add new container?

Q2: When DB2 add new container, whether the new container is added as new stripe set, or added as existing stripe set. I think it should be new stripe set since it can avoid rebalance.

Q3: What's the threshold to trigger size increasing? Can we configure it?

Thanks so much

James

Re: About DB2 Automatic Storage Management

Former Member — Tue, 17 Jun 2008 12:36:29 GMT

Hi James,

Q1: DB2 will increase the size of existing containers

Q2: Automatic storage is designed that it avoids rebalancing by adding a new stripe set.

Q3: To my knowledge they grow in steps of 32 Megabyte

Regards, Jens

Re: About DB2 Automatic Storage Management

Former Member — Wed, 18 Jun 2008 14:05:50 GMT

Thanks for your help.

Re: About DB2 Automatic Storage Management

Former Member — Fri, 18 Jul 2008 07:55:50 GMT

Hi,

Have you got any answer on Q3? Also wanted to know the same thing, if we can set the threshold limit for the auto-extend

Re: About DB2 Automatic Storage Management

Former Member — Tue, 29 Jul 2008 06:24:19 GMT

Hi Eida,

I think you can set these parameters INITIALSIZE, INCREASESIZE, MAXSIZE to control Auto Storage. For more details, you can refer to following link on IBM DB2 web site.

http://publib.boulder.ibm.com/infocenter/db2luw/v8/index.jsp?topic=/com.ibm.db2.udb.doc/admin/r0000929.htm

Hope it's useful for you.

James