Originally posted by: SystemAdmin

Hi,

Is it possible to purge (clean definitly) swap on AIX 5.3? Normally to do so, I have to restart server, which is not secure and desirable considering 24/7 system service.

Server holds Oracle 9i and has a time-window for backup from 300am till 500am. During this time, after backup, I'd like to run a script clearing swap. I'd not prefer to use swapoff/swapon commands because of space consuming for second swap...

Any help will be appreciated.

Thanx a lot,
Reveler
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Originally posted by: SystemAdmin

Why do you want to do this? Put another way, what are you try to accomplish here? AIX 5.3 has an rmps command that will take a paging space out of service. I guess that is about as clean or purged as can be. After that you could use mkps to put it back into effect.

I'm left with the nagging suspicion however that there's more lurking behind this question than meets the eye.

Regards,
Jim Lane
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Originally posted by: SystemAdmin

I am thinking he wants to flush 'pinned' paging space into physical memory for performance enhancements.

Just a guess

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Originally posted by: SystemAdmin

Well, it's related with system performance. It has happened few times we had to restart the server during daytime shift, because performance dropped signifficant. Checking Oracle showed that it's not Oracle fault, after short investigation we think it's swap problem. Unfortunately I can't write more details now, for example processors, disks etc. usage - as soon as the problem occurs again, I write data down and put it here.

If you need some more data about configuration or so, please let me know.

Thanks a lot for help so far,

Reveler
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Originally posted by: steevojb

I don't suspect it's a swap problem more a memory configuration problem or simply, you don't have enough memory.

just before the issue occurs, post output of

svmon -G
vmstat -v

HTH

Steve
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Originally posted by: SystemAdmin

Computer Memory makes up an essential component within any computer system, the memory determines how the computer functions and how many tasks it can perform at any one time.There are many different types of computer memory, ranging from RAM to Gigabytes of Hard Disk space, these different types of memory all serve a different purpose within the computer, RAM memory is used to determine how many applications you can open at any one time, Hard Drive Memory is used to store different files and folders which you can load up when you need them.

http://www.cleanmemory.com/
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Originally posted by: SystemAdmin

These is some new parameters under VMO:
npsscrubmax
npsscrubmin
scrub
scrubclean

Maybe tunning these params, you can clean your swap, without swapping off...

Any one knows about those?

Regards
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Originally posted by: alethad

What I didn't see you show was your system has for memory vs paging amounts. Oracle should be a 1-to-1 but if you don't have enough memory to start with you may need to adjust it a little.
What helped my Oracle system was also setting the system vmo paramters which is in an IBM/Oracle document. Have you done this also? Here are the recommended values if you haven't.
minperm%=5
maxperm%=90
maxclient%=90
lru_file_repage=0

Do you have the "Oracle Architecture & Tuning on AIX" document? I would suggest reviewing over that also.
http://www-03.ibm.com/support/techdocs/atsmastr.nsf/WebIndex/WP100883

Here's another doc that may help or at least keep on file.
http://www-03.ibm.com/servers/enable/site/peducation/wp/9a46/9a46.pdf

Just 2 cents.
Good luck.
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Originally posted by: hwyguy

The easiest way I've found to purge paging space in AIX 5.3 is to remove 1 LP from paging. AIX will then automatically create a temp paging space, delete the old one and rename the temp to your current (i.e. hd6).You can then add back 1 LP to the paging device and you are good.

After that, your paging space can be considered "purged". If you still have much of your newly-purged paging space used, then you clearly have either a VMO tuning issue, or you need to add physical RAM.
Note: For this example, I'm using paging12 as the paging device.
1: Remove 1 LP from your paging space (this may take a while as the new temp space is created): chps -d 1 paging12
2.) Add 1 LP back : chps -s 1 paging12

You can also do this through the "smitty chps" facility.
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Originally posted by: SystemAdmin

Yes, all you have to do is deactivate the paging space. When you do this,
any pages resident on it will be purged back into main memory. Remember
that you need a second paging space of equal size to the space that you're
purging to do this.
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