Usuage of Swap Space


On the mysql 5.0 linux 2.6 kernel . I see the RAM of 2.8 GB is used out of 3.0 GB. And the server slows down almost comes to a hang.

when I do a free -m or top , I always see the Swap is hardly used or not used at all.

Do I have to do something for the server to use the swap space and also how I can see if I have a swap file or partition.

Thanks for any help.

You generally do not want to use the swap space.

On databases where most of the allocated RAM is always used it is very bad to let the DB process get so big that the OS starts to use the swap.
And the general rule is that it’s better to use a bit less memory than risking that the OS starts to swap.

So 2.8GB allocated out of 3G sounds very good.

When your server starts to go slow does it have high CPU or high I/O load?

when the server starts to slow there is high CPU.