Once upon a time, James Antill <james(a)fedoraproject.org> said:
Putting my really old sysadmin hat on, one other reason for
having /tmp, /var and /usr as separate mount points was so that you
could allocate different disk space to each (and they couldn't break
each other) ... do we have other solutions for that?
On a multi-user server (and that includes web access like PHP or CGI),
you really don't want user-writable directories on a filesystem with
anything important, especially security-sensitive things like setuid
binaries. Hard-link tricks are evil. I run with a separate /tmp
(usually tmpfs now) and bind mount it to /var/tmp as well.
You generally don't want logs (which are indirectly user-writable) on a
filesystem with other system-critical things, as it leaves you open to
DoS.
This is really separate from / vs. /usr though, as neither should have
directly or indirectly user-writable files (assuming separate /tmp and
/var).
--
Chris Adams <cmadams(a)hiwaay.net>
Systems and Network Administrator - HiWAAY Internet Services
I don't speak for anybody but myself - that's enough trouble.