on Tue, Dec 02, 2003 at 02:20:05PM -0800, Mark Ferlatte (ferlatte@cryptio.net) wrote:
> Paul Morgan said on Tue, Dec 02, 2003 at 03:49:52PM -0500:
> > > There are currently Debian packages which are needed at boot time which
> > > depend upon datafiles kept in /usr. discover is one of them, there may be
> > > more. In woody, therefor, a seperate /usr can cause problems. Does it
> > > gain you much?
> > >
> > > Why should /tmp be its own partition instead of symlinking /tmp ->
> > > /var/tmp?
> > >
> > > Is there any need for a /boot partition on modern hardware? Why do you
> > > like a seperate boot partition?
> > >
> > > I'm just curious as to the reasoning behind your partitioning scheme.
> > >
> > > M
> >
> > FHS says "The contents of the root filesystem should be adequate to boot,
> > restore, recover, and/or repair the system."
>
> Right... so, again with the "why put /usr on a seperate partition from /"?
> Making / large enough to hold /usr certainly fulfills the req of the contents
> of the root filesystem being adequate to boot, restore, recover and repair the
> system.
See, variously, the FHS, and my own partitioning guidelines:
http://twiki.iwethey.org/Main/NixPartitioning
Among reasons:
- Minimal privileges. / *must* be executable, suid, dev, and is
generally writeable. By contrast:
- /usr need only be executable and suid, and can be nodev and ro.
- /tmp need only be writeable, though it's typically executable
(some temporary scripts expect this), and in my experience only
PCMCIA startup requires 'dev' (my own hacked PCMCIA startup does a
remount,dev of /tmp if necessary, and remount nodev when
completed).
- /var need only be writeable and executable (nodev, nosuid).
- /boot need not be mounted at all.
- Minimal damage. Any actions affecting a partition are limited to
that partition.
- Minimal damage. The probabilities of corruption of a partition are
directly proportional to its size. Minimize the size, minimize this
likelihood.
- Remote-mount / shareable. The FHS states that /usr and /home may be
remotely mounted, read-only if appropriate for /usr. /usr cannot be
split out if it is part of / (though a mount can be made over an
existing directory subtree).
- Minimal systems. Some systems have space constraints on boot media.
In these cases, the root partition must have the tools required for
booting, restoring, recovering, and/or repairing the system. But no
more.
> > /tmp and /var/tmp have different purposes. Check FHS again. Actually, I
> > have both /tmp and /var/tmp on their own logical volumes.
>
> Okay, so neither your /tmp or /var/tmp volumes are available at boot
> time.
The /tmp directory is. If booted to a minimal, root-only filesystem,
it's possibl to write to /tmp. You should, of course, clear these
files if created.
> So, why have a seperate /tmp and /var/tmp?
>
> According to the FHS 2.2, the only difference between /tmp and
> /var/tmp is that data in /var/tmp be "more persistant" than data in
> /tmp, but the only restriction on /tmp is that programs not assume
> that data in /tmp persists between invocations of a program.
>
> In other words, /var/tmp appears to completely fulfill the requirements of
> /tmp, which makes me wonder why they are seperate.
Well, for starters, /tmp *is* cleared between system boots, and is
appropriate for data which *must* not be preserved between boots. The
definitions are not identical, the directories are not equivalent.
You're strongly counseled to read standard texts on Unix administration
such as Nemeth, et al.
Peace.
--
Karsten M. Self <kmself@ix.netcom.com> http://kmself.home.netcom.com/
What Part of "Gestalt" don't you understand?
Moderator, Free Software Law Discussion mailing list:
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