swap space problems

[Mat Davis]

In article <9008081905.AA00985 at fubar> fubar!dap at astro.as.utexas.edu (Damon Permezel) writes:
>I keep getting these warning messages on the console regarding swap space being
>low.  I have added another swap partition, which the system actually
>appears to use:
># swap -l
>path              dev  swaplo blocks   free
>/dev/dsk/c0d0s1  24,1       0  28672  17712
>/dev/dsk/c6d0s1  30,1       0  28672  27776
>
>I still get the warnings, and there is always >90% free on the second device.
>Anyone else experience this problem?

I've been seeing the (apparently) spurious "Swap space running low" messages
for at least a year now, under both A/UX 1.1 and A/UX 2.0.  Unless I know that
I'm running lots of things, every time I've bothered to check I've always had
plenty of swap space.

My guess is that A/UX "walks through" its swap partition as it allocates and
frees space and that the warning is generated whenever it gets "close" to the
end of the space and is about to wrap around to the beginning again.  (I
say "close" because the messages always seem to appear in pairs as if there
are two warning points near the end of the space.)

I've mentioned the problem to people at Apple on two or three occasions, but
under 1.1 the only program that I used regularly that was big enough to trip
the messages was Emacs, and the people I told about the messages assumed that
the problem was with Emacs rather than A/UX (even though Emacs was just *one*
of the things running).

Under 2.0, there's more swapping going on (with a 5M Mac environment running
on a 5M machine) and so I get the message more frequently.

It's just a minor irritation and it's easy to ignore, so I haven't really 
pushed anyone with Apple to look at it.

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                      Mat Davis (davism at vtopus.cs.vt.edu)
                 Department of Computer Science, Virginia Tech
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