swapoff paging space 2

[MoreFeo]

Hi, we have some servers with more than one paging space in a disk (hd6 mirrored in hdisk0 and hdisk1, and another paging00 not mirrored in hdisk1).
We've been told that more than one paging space on a disk (in our case hdisk0) can impact on performance, so we're thinking about increasing hd6 and removing the other.
This is what we are planning to do:
- increase hd6
- swapoff paging00
- rmps paging00

I've read that during swapoff it moves all allocated pages in paging00 to hd6 (that seems logical), so I wanted to know if this can affect in any way on our servers performance and running applications (oracle, websphere, etc...).

Thanks

 

[p5wizard]

Khalidaaa: which link?

p5

 

[RodKnowlton]

cts123,

If the lsps output you posted was captured after the system had been up for a while and under a typical load, removing paging00 and mirroring hd6 will lead to 32%^[†] of paging space active.

As long as you monitor things and don't get a massive memory leak in an application, you should be fine.

- Rod

^[†] Of course, I prefer mine down around 1%.



IBM Certified Advanced Technical Expert pSeries and AIX 5L
CompTIA Linux+
CompTIA Security+

Wish you could view posts with a fixed font? Got Firefox & Greasemonkey? Give yourself the option.

 

[unixfreak]

Wait a sec. swapoff won't necessarily just copy to another paging space I don't think. It will try to load into memory and discard pages that are copies of memory pages, i.e. have been read into memory after being paged out.

Try swapoff, it should work on most of them if they're only 10-25% full. I can't see it will do any harm.

If it won't do it just stop the application, no need to do all this tricky reboot business. That will free up enough memory.

Cheers

 

[khalidaaa]

p5wizard,

This link

http://unix.derkeiler.com/Mailing-Lists/AIX-L/2003-11/0276.html

Regards,
Khalid

 

[p5wizard]

AFAIK there's NO swapoff in AIX433, so cts123 (who hijacked this thread) DOES need that fancy reboot trick to turn off paging00.


HTH,

p5wizard

 

[cts123]

Thanks to all for your time & support.

I appreciate.

Will catch you later..

-Sam