[Soekris] Smallest possible MFS /dev on OpenBSD

[Lars Noodén]

I've got OpenBSD 4.2 on a net4801 and am mounting /dev in RAM.  I'd like
to reduce the amount of memory used even further.  Currently only %4 is
used:
	Filesystem     Size    Used   Avail Capacity  Mounted on
	mfs:21800      853K   34.0K    777K     4%    /dev

What should I be aware of in /etc/fstab to minimize the memory footprint
of /dev?  Currently, I have:
	swap /dev mfs rw,-P/dev.base,-i1,-s2300,-c264,-m5,nosuid 0 0

Random changes to mfs' parameters aren't getting me anywhere.  There
should be a rational way of arriving at optimal settings for mfs:

     -b block-size
     -c fragments-per-cylinder-group
     -f frag-size
     -i bytes
     -m free-space
     -s size

Regards,
-Lars