Andy,

I've seen strange behaviour when we have pushed up the bufferpool
and not also modded the binary to use 8 segments instead of 6. The
AIX server code is built to use 6 segments - equivalent to 1.5GB.

Depending on the number of threads etc I have seen some truly
terrible behaviour in the past, threads crashing, server crashing.
I think I may have seen messaging problems as well - this was some
time ago.  [The memory fades, time is a great healer and all that!]

Best to ask your support centre for the mods you need to do to the
binary and try again.  That gives you 2GB for the whole server.

The other problem you might then see is the server paging out ...
if you don't have quite enough real memory.

[If you are not AIX, then I don't know anything!]

Best regards, Sheelagh