AIX

Hi,
Stats:
AIX 5.3, P590 series. 8 CPUs, 27GB RAM. DB SGA 4GB
MAXCLIENT=MAXPERM% = 20% (MIN IS 10%)
lru_file_repage =1
strict value for maxperm and for maxclient both set to 1.
File system=jfs2.
paging = 1% all the time (means no paging)

Consider the following at point in time:
From vmstat -v, it is clear the file cache is at 19.8% meaning almost all of 20% of 27gb = 5.4gb is in used by cache.

From svmon and vmstat , free memory is 6gb.
From nmon also it says total mem=27gb, free=6gb and used=21gb and file cache used is 5.4 gb.

I would like to know where i am doing wrong below:
Objective:
Try to add the elements/processes and sum it upto 27gb.

Tot_memory = File_cache + unixprocess + shared segment memory +freemem
27gb = 5.4 gb + 9gb + 4gb +6g (as you see i am missing 2.4gb uncounted for)

Running the above at different times more or less am short of 2-2.4 gb always. Where is this 2.4 gb used by???

Filecache, freemem and shared segment calcualtion is pretty much straight forward, and i think you all know how it is to be calcualted. (I even checked ipcs -b and i do not have a memory segment orphan etc).

How I comeup with 9gb is simple.
Running ps vg command and adding (rss-trs)/1024 (mb) to sum for those process ids where PID is also available in (select pid from v$process).
To this i add sum of rss for rest of the remaining process(oracle lile listener, dbconsole) and root processes and all ther processs).

Oracle processs adds upto major like 8gb, rest 1gb is for all remaining processes.

So am sure am doing wrong in calcualting memory from ps vg output. Or is there any other type of mem i misses?

What about jave heap, is this a seperate memory that wont come in ps vg and also in ipcs -b?? Am at a loss.

My only obj for now is to find ways to add all process memory + shared segments + free + file cache and this should sum to 27gb or atleast the difference should not be so high as 2.4 gb missing.
I checked i dont have a leaking unless u tell me how to check??

Cheers

I think this could answer your question, I was curious about this in a similar situation and this was the answer i found. Please read Naggers answer, or i could have misunderstood your scenario all together.

developerWorks : AIX and UNIX : Performance Tools - technical forum : nmon reports almost all memory used ...