Alter bufferpool warning

grofaty · #1 (**permalink**) 08-23-07, 03:01

Hi,
running DB2 v9 FP2 on Linux/Intel I have executed command: "free -m" to get data about physical memory in mega bytes.

Code:

             total       used       free     shared    buffers     cached
Mem:          5067       2010       3057          0         25       1591
-/+ buffers/cache:        393       4674
Swap:         2055          0       2055

The above command shows there is 3057 MB free memory. I have tried to create 524,288 of 4 kB pages to assign 2 GB of memory to bufferpool:

Code:

DB2 ALTER BUFFERPOOL IBMDEFAULTBP SIZE 524288

I got warring:

Code:

SQL20189W The buffer pool opeartion (CREATE/ALTER) will not take effect until
the next database startup due to insufficient memory. SQLSTATE=01657

Any idea why I get this warning if there is enough free memory?

BTW, I could create buffer pool with 128,000 x 4 kB pages = 500 MB. Creating bigger bufferpool always returns above warning.

Regards,
Grofaty

Marcus_A · #2 (**permalink**) 08-23-07, 03:34

This always happens on DB2/Linux. I don't know why, but I just restart DB2.

grofaty · #3 (**permalink**) 08-23-07, 03:38

Marcus_A,
it looks like a bug. I was just little afraid to alter bufferpool beyond available physical memory. I know this can lead to swaping (paging) at OS level.

Is this warning new in DB2 v9?
Thanks,
Grofaty

Marcus_A · #4 (**permalink**) 08-23-07, 03:42

No, it exists in Version 8 also. I do this so infrequently, that I have not bothered to investigate, and I just restart DB2 as the message suggests.

I never got that error on AIX. Maybe it has something to do with the differences in the OS. You can contact IBM for more info.

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