On Sat, Feb 03, 2007 at 07:09:40PM +0100, Christian Biere wrote:
> Michael Parson wrote:
>> 1.  Backups.  Some of us still like to use dump/restore to backup our
>> systems.  Dump only operates on partitions/slices, so we break things up
>> to make those types of backups easier. / /var /usr /home /tmp, etc.
>
> Having all base on a single partition certainly makes this easier.
>
>> 2.  Stability and security.  If you set your system up right, you could
>> mount / read-only and still be able to get work done.  If I keep /tmp,
>> /var, and /usr off /,
>
>> Filesystem    Size      Used     Avail Capacity  Mounted on
>> /dev/wd0h     5.4G     1.3G      3.9G    24%    /usr/local
>
> Seeing this example, I wonder what confuses you to assume that everything
> under /usr has to live on the same partition. I never said, implied or dared
> to put /tmp or /var on the root partition.

Having /usr/local on it's own happened later.  Originally this was
/home, but as /home got bigger, I put in a second disc and moved
/usr/local to it's own partition.

> You did not show what's the difference between /bin and /usr/bin that makes
> it worth to put it on a different partition.

There's more on /usr than just /usr/bin:

$ ls -l /usr
total 41
drwxr-xr-x  10 root wheel   512 Dec 18  2005 X11R6
drwxr-xr-x   4 root wheel   512 Apr 26  2003 aout
drwxr-xr-x   4 root wheel  7168 May  7  2006 bin
drwxr-xr-x   3 root wheel  1024 May  7  2006 games
drwxr-xr-x  47 root wheel  3584 May  7  2006 include
drwxr-xr-x   5 root wheel 10752 Oct  8 00:09 lib
drwxr-xr-x   3 root wheel   512 Dec 18  2005 libdata
drwxr-xr-x   7 root wheel  1536 May  7  2006 libexec
drwxr-xr-x   2 root wheel  1024 Dec 18  2005 lkm
drwxr-xr-x  38 root wheel  1024 Jan  6 15:36 local
lrwxr-xr-x   1 root wheel     9 Mar  3  2003 man -> share/man
drwxr-xr-x   2 root wheel  1024 Dec 18  2005 mdec
lrwxr-xr-x   1 root wheel     5 Feb 21  2005 pkg -> local
drwxr-xr-x  53 root wheel  1536 Feb  1 10:22 pkgsrc
drwxr-xr-x   2 root wheel  4608 Oct 21 08:58 sbin
drwxr-xr-x  34 root wheel  1024 Oct 31 10:11 share
drwxr-xr-x   6 root wheel   512 Dec 18  2005 src
drwxr-xr-x   3 root wheel   512 Jun  1  2000 sup

But there's nothing in /usr that is required to get the base OS running.

> There are very good reasons for placing certain files/directories on separate
> partitions for individual reasons but such a layout is not used by default.
> The default layout is too place certain files on a separate /usr partition
> without any good reason or advantage as it seems.

And I I have not had any good reason or advantage to having /usr on /
either.

-- 
Michael Parson
mparson@bl.org