Preamble...
I've been playing with memory pools the past two weeks. I also installed
iDoctor to learn more about what is consuming CPU/memory/IO. I have set
QPRFADJ to '0' so I can adjust memory pools and have them stick.
Side note: Memory pools rock. Very cool feature, IBM i.
Questions...
- Is it a bad idea to set QPRFADJ to '0'? My reason is that I don't want
the *INTERACT pool to have much because I'd rather it be dedicated (always)
to *BASE (where my open source/ssh is running).
- In reviewing iDoctor ActiveJobs screen it appears my 5250 sessions are
the only things operating on *INTERACT, so I think I am safe lowering this
value from 600MB to 40MB. Having it at 40MB hasn't been uncomfortably slow
(going on a week now). Are there any gotchas with setting it so
low?(i.e. other types of jobs that I am not yet seeing)
- The IBM docs(n1) say "The memory pool size should be large enough to keep
data transfers (paging) at a reasonable level as the rate affects
performance." Well, the obvious next question is "what is reasonable"? I
consistently see "Active Wait" for *BASE at 3200-3500 and "Non-DB Faults"
around 15 and "Non-DB Pages" around 37. This seems like a reasonable amount
of faults given I am trying to do a variety of heavy lifting things all at
once. This would also lead me to believe my system currently has enough
memory at its disposal and if I am looking for next areas of improvement I
should look to CPW.
n1 -
http://bit.ly/ibmi-about-memory-pools
Aaron Bartell
litmis.com - Services for open source on IBM i
midrange.com
