Subject: Re: Why root and usr in separate partitions?
To: None <firstname.lastname@example.org>
From: Steven Grunza <email@example.com>
Date: 06/29/2001 10:14:12
Backing up and protection come to mind as well. The /usr directory can
most likely be mounted as read-only in most instances. Once the system is
stable, switch /usr to read-only and make a backup of it. You'll only need
another backup of it if you ever switch it out of read-only. Not that I've
done this yet but it's on my list of things to do.....
At 09:19 AM 6/29/2001 -0400, Nate Johnston wrote:
>Scott Horton spake thus: (Thu, Jun 28, 2001 at 10:43:10PM -0500)
> > So - my question - in a single-disk system, why this longstanding tradition
> > of breaking the filesystem up into multiple partitions? (There! I've
> > unveiled my ignorance of *nix filesystems in general!)
>First, there is no reason requiring this kind of a split. I have seen
>plenty of systems, particularly desktops, that have one gigantic /, and
>the only other filesystem is swap. While this is generally considered
>Bad Form it is ok for a desktop.
>Second, Unix has its roots in multi-disk server systems. Your laptop
>running NetBSD thinks more like a Sun Starfile E10000 than the same
>laptop running Windows. So, when I as a system administrator administer
>large produciton unix systems I configure my desktop unices to be
>similar. Given the roots NetBSD has in old unix, and people like me who
>have a utilitarian reason to make their laptops look vaguely like their
>servers, more people accept multi-filesystem setups as the norm.
>Third, it increases functionality through modularity. I have to keep my
>work data separate from other data as a corporate requirement, therefore
>when I go into work I use a different /home partition on my laptop than
>when I am at home (using the automounter). Since filesystems are a
>relatively static part of the system this doesn't usually come up much
>but it is there.
>Lastly, having multiple filesystems localizes errors. If there is a
>physical disk error, chances are that it is unlikely to be in the small
>center track that contains my root and other boot-critical filesystems.
>It is likely to be on an exterior track, where my /home, /export, or
>/usr live. The same process works for localizing application level
>errors; here is an excerpt I got from a general google search "why does
>unix use separate filesystems". It is representative of the philosophy
>and the mentality.
>"You want to control how much data gets put on a drive. For example, in
>some environments, I'll make /var/spool/lp/temp a small filesystem of
>its own. This causes it to fill up if there are too many unfulfilled
>print jobs, which calls attention to the problem before it really gets
>out of hand and fills up something more important. The idea here is that
>it's better not to print than not to work at all."
>Nate Johnston firstname.lastname@example.org
>GPG footprint: DEAF B505 0D84 1AEF A43F 91C5 71B3 D053 D0E1 3C05
>Unix System Administrator SingleSignon.net