/usr/home vs /home (was: Re: One or Four?)

[Polytropon]

On Sat, 18 Feb 2012 00:05:49 -0600 (CST), Lars Eighner wrote:
> It seems to me that partition and mount point are being confused to a
> degree.  There is no reason what is mounted at /usr/home cannot be a
> separate partition as well as if it were mounted at root. 

I thought of this fact as such an obvious thing that I
didn't bother even mentioning it. :-)

Of course, /usr/home can be a separate partition (even on
a separate disk), just like /usr/ports or /usr/obj or even
/usr/local could be. I've also seen systems having several
subtrees in /export, each one being on an individual partition,
some of them even on an own disk.



> There are some
> good reasons for the user directories (and perhaps some other data) to be on
> a separate partition - mostly the reasons relate to ease of back up and
> migration whether planned or emergency.  Arguments about where to mount that
> partition are not so practical, being more in the philosophic and historical
> realm. Pick one, recognize not everyone will be on the same page and put
> appropriate links in.

I'd still be interested in why this particular location has
been chosen. The typical access path for home directories
is /home (that's why the symlink), and as long as this
"top level entry" points to the proper data (no matter where
they are located), it should be fine.



> There may have been a historic reason, but now it is philosophical - trying
> to keep the system and userland distinction clear.  But there are many flaws
> in the attempted separation. /var for example is the default location for
> many logs, both system and user, the spools (remember news?), and databases.
> You really cannot drop /usr into a different system and have an operational
> result.

Correct. Also see the difference in usage interpretation for
/tmp (not guaranteed to be present after reboot) and /var/tmp
(should be present in the same state after reboot).

The separation of concepts FreeBSD is famous for basically is
"the OS" (primarily /, /etc, /(s)bin, /usr/(s)bin) that provides
the minimal functionality to bring up the operating system even
in worst case, where only the root partition needs to be mounted,
which can be done in read-only mode, to finally reach the single-
user mode, and "3rd party applications" (everything in /usr/local).
However, both system and 3rd party programs access things in /var
or /tmp. Not having actual _user_ data in between can be a benefit
especially when something goes wrong.



> (I put the home directories, the www directory, databases and spools all on
> the same physical partition which I mount arbitrarily at /usr/local/data. It
> isn't exactly plug-n-play, but in tests and emergencies is has proved
> practical to drop the partition into several linices with a high level of
> functionally  - depending on application versioning being close to in sync.)

And I assume you still have /home pointing to the correct location
on that "new" path?


-- 
Polytropon
Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...