On Mon, 25 Dec 2000 salvage@plethora.net wrote:

# 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.

What if there is no "primary swap partition", i.e. nothing is compiled
in and you have more than one swap partition mounted at equal priority?

I would think that swap is treated as a chunk, as opposed to being split
out into the respective devices of which it is composed, unless, of course,
you assign different priorities to different devices.

# >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.)

I'm not sure what you mean by /dev/partition, here.  Do you mean
"/dev/$overlap" where overlap=[some-disk]d for i386 and [some-disk]c for
most others?

You seem to be right about the default size, though (about 8M).

# -- 
# T. M. Pederson <salvage@plethora.net>
# "I'm not talking about people here; I'm talking about me." --anon.
# 


				--*greywolf;
--
*BSD: Multi-platform OS