On "Mon, 25 Dec 2000 15:39:45 +1100", "Jenkins, Graham K [IBM GSA]" <Graham.K.Jenkins@team.telstra.com> wrote:

>Guys (and others) - I have been playing with memory filesystems
>to place /tmp in swap space.  The examples in /etc/fstab.sd show:
>  /dev/sd0b /tmp mfs rw,-s=20000  0 0
>
>That's OK - but what if you have multiple swap partitions and
>wish to spread /tmp over all of them?  Perhaps ..
>  swap      /tmp mfs rw,-s=20000  0 0  ??

I'm not 100% familiar with mfs, but I don't think that's an option.  I
think that calls for some RAID functionality, and I don't recall seeing
that in the source for 'mount_mfs'.

Specifying 'swap' as the base device pulls up defaults based on the
primary swap partition.

>And what if you leave out '-s=20000'?  Depending on OS version
>it seems that half memory size - or half total swap - is assigned?

ISTR that it depends on whether you specify 'swap' as the base device
or explicitly provide the "/dev/partition".  The default default is
16384 blocks --- 8 Mbytes.  I think if you explicitly provide the
"/dev/partition" it will read the label and use the size of that.
(Somebody correct me here if I'm imagining things.)
-- 
T. M. Pederson <salvage@plethora.net>
"I'm not talking about people here; I'm talking about me." --anon.