Subject: Re: Why root and usr in separate partitions?
To: Scott Horton <>
From: Manuel Bouyer <>
List: netbsd-users
Date: 06/29/2001 16:45:32
On Thu, Jun 28, 2001 at 10:43:10PM -0500, Scott Horton wrote:
> This is just a generalized *nix question, really.
> I'm not new to *nix, but I've never spent the requisite time to become
> knowledgeable about it.  Generally, I've just done enough to solve a
> problem, then went back to other things.
> I *have* however, been at it for a while (TRS-80 Model 16 Xenix running on
> was probably my first exposure) - and I've noticed that there's a
> longstanding tradition of breaking up a perfectly nice single hard drive
> into lots of little partitions for different sections of the file system,
> such as root, /usr, /home, and so forth.  I've always wondered about this -
> it seems kind of wasteful, especially in an OS that allows you to define
> your own block and cluster sizes (unlike FAT16, FAT32, etc).  I do
> understand that SWAP is normally a separate partition, because it's not
> (usually) a traditional filesystem.
> 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!)

This is mostly a matter of usage. reasons to break the disk in several
- separate portions of disks for different use: you don't want a user
  filling up /var/tmp break logging function, or make mail receiving fail,
  or ...
- I have some machines here user-writable partitions are mounted nodev,noexec
- Also, with a small '/' partition, if you have some disk damage you have more
  chances to have '/' intact to be able to recover from the disaster.

Now, this is important only for "critical" machines. On dataless, client
machines I have only one big partition.

Manuel Bouyer, LIP6, Universite Paris VI. 
     {Net,Free}BSD: 22 ans d'experience feront toujours la difference