memory not getting release

[sapfan1971]

Hi,
I have installed SAP on HP-UX VER 11 and have 5 gb ram and the problem is even the SAP process ends or user logs the memory does not get relaese the machine gets terribly slow and we have to reboot to free memory. I was searching on google and saw in IBM AIX someone faced the same problem and solution someone suggest you should set nmperm should not be more than maxperm then u will have virtual memory available. If u think this is correct , can u suggest how to do it

[Dennis Handly]

>HP-UX VER 11

This isn't helpful, what is the version?

What does "ipcs -ma" show?
What are the values of the kernel parms: dbc_min_pct dbc_max_pct

[sapfan1971]

Pls. find the details in attachment

[sapfan1971]

some more attachment

[Don Morris_1]

First, you have 6Gb of RAM, not 5. Just thought you should know.

vmstat shows you have page outs, and swapinfo shows:

eccdev: /#swapinfo -tam
Mb Mb Mb PCT START/ Mb
TYPE AVAIL USED FREE USED LIMIT RESERVE PRI NAME
dev 20000 4190 15810 21% 0 - 1 /dev/vg00/lvol2
reserve - 7429 -7429
memory 5839 2217 3622 38%
total 25839 13836 12003 54% - 0 -

So you're oversubscribed by about 4Gb. You've got 7.9Gb in sysV alone (from the ipcs output) the bulk in segment 1540101 (probably the Oracle SGA with Oracle as a parent) of 1.7Gb or so... and then a 4.6875Gb segment of SAP with 20 attached. Assuming both of those see accesses... that's quite likely the bulk of the User memory load -- and they're fighting with vhand.

Being a Oracle/SAP configuration, you could try lowering filecache_min to get the reserved memory back from the system -- but we're only talking 100Mb tops... and your memory deficit dwarfs that. You've got enough filesystem activity going on that the metadata shows up in the top of the Arena listings (VX inode/global cache, File Cache metadata, etc.).. tuning the VxFS inode maximums might get a little bit of that back, but again -- I wouldn't think that much.

So -- I would expect the memory doesn't come back on a single process exit or user logout because there's still more SAP and Oracle out there... and the SysV segments shouldn't go away until all the attached processes go away. (In other words you would need to do a graceful stop [not kill -9!] or SAP and Oracle to get them to release this memory).

Or in other words, I think you need to either tune Oracle/SAP more appropriately for this box (smaller SGA / whatever SAP uses SysV for) or add about 6Gb of additional memory. What you're running now is simply too much for this box to be performant. Even if you got 1Gb back from System use (which is about the best you could hope for in reality), that would still leave you at least 3Gb short for your workload.

[sapfan1971]

how can I do setting of maxperm as it should be lower than nmperm . Meanwhile what are other means we can use the virtual memory . As while purchasing server we had taken oversized server ..Problem is SAP says it is OS level issue and HP says it is application.

rgds

[Patrick Wallek]

You are trying to use AIX theories/kernel parameters on HP-UX. That isn't going to work. Kernel parameters are not standard between flavors of Unix.

The parameters nmperm and maxperm do NOT exist on HP-UX, so there is NO way to set them.

[Dennis Handly]

>how can I do setting of maxperm as it should be lower than nmperm.

As mentioned by Patrick these don't exist so you'll have to tell us what they do.

>Meanwhile what are other means we can use the virtual memory.

You are using 54% of it.

>As while purchasing server we had taken oversized server.

As Don says, it isn't oversized now, you need to add more memory or reduce the load.

>Problem is SAP says it is OS level issue and HP says it is application.

They probably should have said it is a load issue. You may be able to tune Oracle and SAP to use less SGA and shared memory.