swapspace increment in mirrored root disk

[ASIFKHAN]

After I added RAM in system.I have 2 root disks in vg00 and both are software mirrored.i want to increase the swap space by 12GB and also each of these disk is having 30GB of space empty.Can anybody tell me the steps how to increase swapspace along with synchronization(taking care that they are mirrored with each other)??

[Steven E. Protter · Accepted solution]

Shalom,

Just an aside, but how are you calculationg your swapspace need? Your system has a lot of memory and using the twice ram formula may not be required.

How to increase it:
1) Use SAM. If there are two disks with space on it, most of the time sam will get it right.
2) use lvsplit or lvextend -m 0 to break the mirror on the swap logical volume (usually lvol2), remove the mirror swap logical volume, lvextend the primary swap, use lvextend -m 1 to mirror the swap partition. Boot. Done.

I don't like approach 1 because sam does make mistakes. Some people by the way will advise you against mirroring swap at all. Thats a matter of perference. I'm an agnostic on the subject.

A boot will be required in either case for the system to use swap.

Here are some documents.

Designing swap space allocation:
http://docs.hp.com/en/B2355-90672/ch06s03.html
Memory management white paper.
Storage and increasing swap space.

Option 3.
Add new swap space. Set the priority lower so it does not get used except when the system is under stress. That way if you don't need it, you don't impair system performance.

SEP

[ASIFKHAN]

thanks for support and reply