Hi:

I am adding new containers to existing tablespaces and during the rebalancing process, database hang for 5 to 10 minutes. During this time I can not do anything e.g. connect, list tablespaces, get snapshot etc. commands. But if I was already connected the database prior to hanging I can do most SQL operations but no db2 or CLP commands.
Containers are quite large 20G and I am adding two of them to existing two (total of 4 containers at the end).

Has anybody noticed this behaviour before and any idea why would it hang?

DB2 UDB V8 FP3 on Windows

dollar

mmm ... I have seen a system hang when rebalance is in progress ... I think it is primarily I/O contention and also other resources used by the rebalancer ...

The system hang has also happened to me when I was creating a 40 gig tablespace .... I got an error saying that maximum number of processes have been allocated to db2 ... but for sure , it wasn't ... A PMR with IBM did not really help ... The conclusion (!!???) at our shop was that even the resource required to create a connection was not available ....

(A painful byproduct of this poblem is that the management has strictly said 'No tablespace creation or extension before 10pm )

Well, when the database hang, CPU usage is only around 10% and lot of memory available as well. I think DB2 gets confused somewhere or goes to sleep....can't think of anything at this time. But for DBA's who are considering adding huge containers in future please keep this behaviour in mind.

dollar

A question I have :

How many db2rebal processes can a tablespace use ? Can rebalance exploit SMP parallelism ?

Thanks for your thoughts

Sathyaram

One thing I found during my investigation was that reblance process will hang if user is trying to execute the snapshot command. DB2 calls it a deadlatch state where both processes are trying to acquire latch of another one. So, DO NOT ISSUE SNAPSHOT command during rebalancing process. I was actually taking the snapshots at various intervals to see the progress!!!

About the no. of db2rebal processes, I think it's only one (just a guess)

dollar