Subject: Re: Minimum swap size
To: David Laight <>
From: Simon Burge <>
List: tech-kern
Date: 05/19/2003 19:56:21
David Laight wrote:

> > I think we'd want at least a minimum of say 64MB of swap for any system
> > that is low on RAM - gcc/g++ can be a pig.  I've got 150MB of swap on a
> > 8MB system here, 48MB wasn't enough to do a native build.
> This is consistent with saying that you need enough swap for the
> workload...  I guess that system takes a while to do anything
> because it is swapping like mad - but at least it then completes.

Exactly.  One of the gcc self-tests takes about 12 hours on this box and
a little over a minute on my althon :-)  But it does complete...

> Actually seems like larger of 128MB and memory size would be a
> moderate default.  Maybe with some space stolen for small disks
> with lots of memory.
> My actual plan is to display the sizes of the various partitions
> and the total amount of free space on the disk (netbsd ptn if mbr).
> Then let the user change any of the numbers until they are happy.
> Probably allowing separate /usr and /home and /var?.
> > I'm using 4GB / + 4GB /var + 2GB swap + 128MB mfs /tmp on an 80G disk
> > on a system with 512MB of RAM.  This seems about right for me; lots
> > of spare space, but doesn't seem overly wasteful.  For example, I
> > installed the linux openoffice not long ago.  It's over 300MB including
> > dependancies, but my root fs is still only 40% full.
> Do you have a separate /usr?

Not any more.  root, /var, swap and "everything else", with nullfs mounts
for /home, /usr/src, /usr/obj is my standard layout these days.

I'd also like to see some smarts (that I proposed ages ago, maybe
on tech-install) that had some way of knowing if the chosen layout
(catering for separate /, /usr and /var or combinations of those)
would let an install fit, before the sets were extracted.  For
example, setting up a 4MB / and 500MB /usr just doesn't work.

One idea is to include a small file with each release that lists
the /, /usr and /var sizes for each set, and for sysinst to fetch
and parse that file before doing the partitioning.  You also want
to indicate that whatever partition that holds /usr can possibly
grow quite a bit if you are going to use pkgsrc.

Lots of ideas, so little time...

Simon Burge                            <>
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