[plug] shared swap partitions?

[Craig Ringer]

On Wed, 2004-05-26 at 23:49, Chris Caston wrote:

> In fact I think it is better to have your swap partition on a different
> drive/controller for performance reasons.

This depends a lot on what the two disks are. If they're both the same
type of disk, then sure. On the other hand, it's probably not worth
putting swap on a spare 500MB HDD you had lying around, when you've got
a 250GB 7200RPM SATA disk as the main disk. The main disk can read an
area the size of the entire small disk in a few seconds, and that speed
difference - plus the much faster seek times - is likely to completely
outweigh any benefit of having swap on another spindle.

I've seen a system set up like this, and it was horrible - it didn't
have enough RAM, so it was swapping a lot. Moving the swap to the main
disk produced a significant speed improvement, even though swap was then
competing with normal disk access.

Like anything else, though, it'll depend on your workload, the amount of
swapping you do (when, how much, and how often), etc.

Craig Ringer