[OmniOS-discuss] [discuss] to swap or not to swap

[Bob Friesenhahn]

On Thu, 18 Apr 2013, Paul B. Henson wrote:

> I'm just about ready to deploy the home storage server I've been working on 
> for a while, and am trying to decide what do about swap. The box has 12 3TB 
> drives configured as two 6 disk raidz2 vdevs and will have about 300G of 
> L2ARC. Right now it has 32G of memory. I ended up deciding to have a separate 
> virtualization server so this one is pretty much only going to do file 
> service via CIFS/NFS.
>
> The rpool is going to be an SSD mirror, I don't know that I want to put swap 
> on it. Technically, you can run illumos with no swap at all, but somehow that 
> just feels wrong :). I suppose a box with 32G of memory is in better shape 
> than one with 16G of ram and 16G of swap... The third option would be to put 
> the swap volume on the data pool, but I'm not sure if there are any issues 
> with swap on a raidz2 pool.
>
> Any thoughts?

Unless you are like me (run large memory-hungry apps), you are 
unlikely to need any swap with 32GB of memory.

On the flip-side, any swap that you do define on your SSD is unlikely 
to see any significant activity so it is unlikely to harm your SSD.

Solaris will reduce the size of the zfs ARC before it starts filling 
swap.

Bob
-- 
Bob Friesenhahn
bfriesen at simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer,    http://www.GraphicsMagick.org/