Subject: Re: Separate /usr, etc...
To: Greywolf <>
From: Greg A. Woods <>
List: current-users
Date: 12/15/2002 15:43:03
[ On Sunday, December 15, 2002 at 09:35:58 (-0800), Greywolf wrote: ]
> Subject: Re: Separate /usr, etc...
> Our defaults are grossly misconfigured considering that if /var isn't
> configured, guess where it goes?!?  Given the above default settings,
> that's not well thought-out.

While I disagree with you vehemently about /usr (well, on anything with
any more than about 500MB total disk space), I do agree 100% with the
stupidity of the current defaults suggested by sysinst and/or the few
remaining INSTALL scripts.

The only time it makes sense on any semi-modern system to keep /usr as a
separate filesystem is on diskless systems where sharing /usr helps save
a tiny bit of disk space.  But on diskless system's it's not really a
separate filesystem, but rather just a separate mount point on a server
somewhere (perhaps even mounting the /usr sub-directory of the server's
root filesystem, as I usually do).  For my diskless sparcs I keep their
root mount point on the server's root fs with hard-links to their /bin,
/sbin, and other sharable stuff like the /etc/rc.d scripts and so on.

I believe /var really MUST be a separate filesystem, regardless of the
system's resources, purpose, etc.  It is almost insane to leave it on
the root filesystem, even if you're booting diskless, though at least on
a diskless system it's not so very bad.

/tmp really SHOULD be a separate filesystem (and on large RAM general
purpose machines it should probably be "mfs" too).  (sometimes on some
types of machines /tmp gets so rarely used that having it on the root
filesystem isn't too big a deal, but if you have users....)

By default every spindle should have some swap space on it too, and the
primary swap partition should be the size of the maximum (expected or
possible?) RAM capacity of the machine so that crash dumps can be saved.

Beyond that the real issue, on modern machines at least, is what to do
with all the rest of the space.  Typically you'll want a good bunch of
space for /usr/pkg and/or /usr/local, and then if you're going to have
user accounts on it you'll want /home too.  If not though what I
normally do after that is lump all the rest in a big /work partition and
let it get used as necessary.

I suppose ideally, on modern machines especially, all individual disks
should be mirrored, especially for root and swap partitions, and all
other file systems should be at least mirrored, if not RAID-5.

I recently partitioned a machine with a 40GB and 80GB drive.  It is a
commodity PC and quite inexpensive too.  It is just to be an
SMTP/DNS/HTTP server for a dozen people in a small office.  I still
don't know what to do with most of the available space on that machine.
I should probably have pulled the 80GB drive and had them go get an
identical 40GB to use for RAID-1.  Maybe we'll do that soon anyway.
Unfortunately it's running Red Hat's OS.  What we did to with a tiny
amount of that space was install three CD's worth of applications just
for fun....  :-)  An equivalent M$ setup would have cost in the order of
tens of thousands of dollars in software licensing fees, and probably an
extra bug for every $100 worth too!  :-)

								Greg A. Woods

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