Cannot add or extend containers without affecting users

[Former Member]

DB2 V8.2.2 on AIX 5.3 on Regatta/Shark.

When adding or extending containers the db server is not responding and SAP system freezes.

During adding or extending the disks are 100% utilized and the CPUs are in wait (for I/O) state.

As a result I only add og extend containers in the night

Anyone got the same experience?

How did you solve it?

Regards, John.

[Former Member · Accepted solution]

I suppose the rebalancer kicks in on your system. You can check that by retrieving a tablespace snapshot.

Rebalancing takes place for example if you add containers to an existing stripe set. You can avoid that if you add containers to a new stripe set or by just extending the container of the last stripe set.

The performance of extending tablespaces can be improved by using the fast container allocation. To use this you need to update your AIX system with all recommended patches from and than turning on DB2_USE_FAST_PREALLOCATION by issuing

db2set DB2_USE_FAST_PREALLOCATION=ON

[Former Member · Accepted solution]

The problem is only occuring when the "alter tablespace ... add/resize" command is running and the containers are allocated in the file system.

When containers are allocated the command exits, SAP system is availabel again and db2rebal starts.

No problems during db2rebal.

DB2_USE_FAST_PREALLOCATION looks more like it.

Thanks.