Determing size of swap space

UNIX HP-UX
1

Hi Experts,

Need your advise in determining the size of swap space in of the new HP-Ux server.

Server is having 32G of physical memory.

Ideally what amout of physical memory should be allocated as a swap space?

Following document from HP suggests to have minimum swap space equivalent to physical memory on the system.

http://bizsupport1.austin.hp.com/bc/docs/support/SupportManual/c02281492/c02281492.pdf

I am confused if it will suffice or I need to more swap space,kindly advise.

Thanks in Advance!!

2

There is no definitive answer. The amount of swap space you need depends on many factors beyond the size of the installed RAM. In any case, too large a swap doesn't hurt, too little can have very adverse effects.

3

There was a time when you used to multipy by 2 or 3 (HPUX9-HPUX10...) then came the lowcost of RAM with servers supporting a lot and so some configuration went on with loads of RAM but then we saw issues like "How come I get < no more memory to load...> when I have 16GB of RAM and we seem to use only 12?> etc... Im glad to see HP changed it point of vue to swapsize=RAMsize, but it is only to not see anymore the previous in support...
As jlliagre explains, only you can answer for we dont know what you are running, nor how much disks space you have nor the type (yes it has its importance...). For performance I suggest if you were to create 32 GB swap device to create 4 of equal size...(load balancing...)
Tell us more what you are trying to achieve, we give you our point of vue, tuning is the art or compromize (which is the best for you?) knowing what you need to achieve is the way to go, you can finish like me 10 years ago having tuned a K360 with only 2GB RAM to run 6 oracle instances (of three diff versions...) with a sybase, and ftp server 24/24 and approx 600 users concurrent... without any performance issues...