Hi ,

I have one clarification of setting swap space in Linux EL server. Generally the swap space is double of the memory that server has, AS per my dell poweredge server , it has 4GB RAM by default. Could that be possible to set swap the double of Memory as 8 GB?.

Thanks

Are you asking if it is possible to set the swap to 8GB? As long as you have 8GB of space to allocate to swap, it is. I once created a 60GB swap on a spare partition because something I was doing was using all my RAM and all my swap.

Are you asking if you need to set the swap to as much as 8GB? The 1x's to 2x's RAM thumbrule was derived in the days when hard drives weren't even 4GB. IMO, it depends on what you're going to be doing with the machine. I still follow it on my machines with 2GB or less (I use 1x's), but rarely do I see it being used extensively. On my machines with 4GB, I set it to 2GB. But, these are not machines being used in a business environment.

I that's not a rule is a suggestion, and of course it depends on your aplications.

I created a 6gb swap in a 64 bit kernel 2.6 .

in the days of 2.4(i think ) you can use more than 2.0 gb of swap but in diferents partitions. I dont know for the kernel 2.6 - 32 bits and exist a limitation.

In a dns server I only use a swap partition whit the same size of the phisical ram, and have no problems, of course monitoring the swap and if it increase to much , better increment the ram.

here the evidence.

Mem: 3092140k total, 3070240k used, 21900k free, 164004k buffers
Swap: 5855640k total, 980k used, 5854660k free, 2448580k cached

If your machine starts to swap it will slow down dramatically. The solution to a swap performance problem is not to increase the amount of swap space. Instead you would either buy more RAM or decrease the number of programs that you are trying to run simultaneously. Therefore 512 Meg is enough swap for anybody.

The one exception is if you use the suspend to disk function. Then you will need a swap size of about 1.5 times your RAM size in order to accommodate suspend to disk.

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Steve Stites