how much swap to add?

[Dave Chamberlin]

Hello, I have an rp8400 that need more RAM and has gone from 20GB to 32GB. I have pseudoswap enabled and about 9GB of device swap (lvol2=4GB and swap2=5GB in vg00). I have enough free space in vg00 to create another swap of 12 GB (the amount of RAM I added). Is that reasonable?

[Pete Randall]

Probably more than reasonable. I think I would add another 9GB and save 3GB for any emergency vg00 expansion in the future.


Pete

[Jaime Bolanos Rojas.]

Dave,

Usually you would like to have at least the same amount of memory available in swap space available, other people prefer twice the size of memory to be on the safe site.

If you comply to the above rules, then you should not have pseudoswap enable on the machine, psuedo swap is only enable is you have less swap space available than the actual physical memory use on the system.

Regards,

Jaime.

[Steven E. Protter]

Shalom,

You could add none. I think to meet dump requirements if dump and swap are the same device you need a minimum of 16 GB to have a stable system.

SEP

[Dave Chamberlin]

I am not sure I can add as much as I want - I have maxswapchunks set to 7000 and swchunk is 2048 - does that mean my ceiling on dev swap is 14GB? Thanks

[Patrick Wallek]

I believe so.

This is one reason I always max out maxswapchunks to 16384.

[Jaime Bolanos Rojas.]

Dave,

This old thread should answer your last question:

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=1040963

Regards,

Jaime.

[Dave Chamberlin]

Well I will add 4G now and reconfigure the kernel to increase maxswapchunks when possible to get the rest - I will put it on my VA array instead of vg00 to not overload the system disk...
thanks