swap space

[Allan Palma Faylona]

Hi,

I was about to install hp-ux 11.0. I little bit confuse on how much swap space will i put into. It's i type in half the size of my physical memory or twice the size of my physical memory.


thanks

[KapilRaj · Accepted solution]

It is better to have equal or more than the ram as it id used as the dumb device as well.

But If you have more than 8 GB of RAM i would not go for more than 8 GB swap. 'cause It is'nt necessary and incase the system dumps it does not dump the whole 8 GB.

Regds,

Kaps

[Sridhar Bhaskarla]

Hi,

Twice the size of physical memory was old rule. There is a kernel parameter swapmem_on and is enabled by default. It covers 75% of the swap area called pseudo swap. However, depending on the memory utilization, the amount of memory available for swap allocation may gradually decrease over the time. So I suggest you add device swap equal to the size of your memory. Note that swap from memory is only for reservation purposes not for actual use.

Once the system is up and running, run 'swapinfo -t' at regular intervals and see the %utilization. If you see at around 90%, then it will be time to consider adding more.

-Sri

[Sundar_7]

Depends on number of factors. to cut the long story short

1) If I have huge physical memory (say like > 4 GB) then I would probably enable pseudo swap (which is enabled by default) and make my swap to the same size as my physical memory

2) If the physical memory is relatively small, then I would make my swap space twice (or 1.5 times) that of physical memory in the system and disable psuedo swap.

[Michael Tully]

Please let us know:

What database you intend using, if not what application?

Also how much memory you currently have. There used to be an old rule of 2xRAM=Swap but this depends largely on how much RAM you have.