> >           + For mfs(8) filesystems - classically mounted on /tmp in order
> >             to speed up any programs using /tmp, by adding the following
> >             to the fstab(5) file:
> > 		    swap  /tmp  mfs  rw,-ssize 0 0
> >             where size is in 512byte blocks. The space required
> >             is taken from the swap space as the filesystem is used.
> 
> I always wanted opinions on whether the "async" flag should be specified here.
> I use it on some of my systems:
>      swap /tmp mfs rw,async,-s100000  0 0
> 
> Theoretically, "async" should be faster. I didn't notice a performance increase
> with "async", though, but it didn't hurt either.

What conditions or speed advantage are gained by using mfs vs no mfs?

Where is using mfs most useful and where is it least useful?

.....

> >           The 'correct' value for swap is dependent on the usage of the
> >           system, but a general rule might be the larger of RAM or 32MB.
> >           Another good rule is to always try to split swap across as many
> >           disk as possible to increase the available swap bandwidth.
 
> IMHO, this is too small a value for swap. .....

.....

> My personal decision on swap space is 2.5*RAM, with mfs limited to half of the
> swap space.

IFF mfs was not used, would the 32mb swap still be too small?
I my case, I may want to clone a boot drive as an emergency spare backup.
In that case, a small 300mb drive would be fine for that.  I could always
dump onto a larger drive with more swap after the system was brought back up.

In your 2.5*RAM mode, are you actually using only 1.25*RAM as swap,
with mfs operating?

Good discussion..... lots of neat insights to learn.

Bob