[plug] large swap space and raid array

[Craig Ringer]

On Thu, 2004-01-29 at 23:37, Denis Brown wrote:
> Okay, split up the swap into different partitions across different disks!
> Err... yes, but here I have all my "disk eggs" in one RAID array "basket."
> So I have this gigantic SCSI drive staring out at me, all /dev/sda of it.

That's actually going to be a problem. The performance of swap volumes
on RAID 5 is ... distinctly inferior, and you will not want to be
swapping much at all. I set up my server with a RAID 1 volume for /var
(databases, mail), the OS data, and swap for that reason. All the rest
of the data goes on a much larger RAID 5 volume.

> I'm getting a feeling in my water that LVM as mentioned by Craig Ringer
> and others on this list, might be the sane way of going.   But I didn't
> want any extra complications :-)

As it happens, I keep two 2GB swap volumes as LVM logical volumes :-P

It probably is the way to go, and LVM is _so_ wonderful to work with. Of
course, I was using RH, and their installers natively support LVM - that
makes things a lot easier.

There's very little nicer than snapshotting your server - live, with
volumes mounted r/w and in use - and writing backups of the volumes to
tape over the network.

> Given the sheer amount of physical memory, is a
> smaller swap a safe choice (ie.2GB?)

Maybe ... but there's no harm in having lots anyway. 

Craig Ringer