Sysinstall automatic filesystem size generation.

[Mark Kirkwood]

C. Michailidis wrote:
> 
> This is a very straight-forward way of doing things.  Do you really think that sysinstall should use a similar method when it attempts to auto-configure a slice?
> 
> From what I understand there are quite valid reasons why you would want a seperate /, /var, /tmp, and /usr.  For some reason I recall being informed that more critical filesystems should reside closer to the beginning of the disk.
> 
> I'm not too sure why, maybe someone would care to explain why it isn't the best practice to have a single monster /?  I have simply come to accept this as fact and wouldn't mind a refresher myself.
> 

The handbook
(http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/disk-organization.html) 

has quite a sensible discussion about this:

<quote>
Different filesystems can have different mount options. For example,
with careful planning, the root filesystem can be mounted read-only,
making it impossible for you to inadvertently delete or edit a critical
file. Separating user-writable filesystems, such as /home, from other
filesystems also allows them to be mounted nosuid; this option prevents
the suid/guid bits on executables stored on the filesystem from taking
effect, possibly improving security.

FreeBSD automatically optimizes the layout of files on a filesystem,
depending on how the filesystem is being used. So a filesystem that
contains many small files that are written frequently will have a
different optimization to one that contains fewer, larger files. By
having one big filesystem this optimization breaks down.


FreeBSD's filesystems are very robust should you lose power. However, a
power loss at a critical point could still damage the structure of the
filesystem. By splitting your data over multiple filesystems it is more
likely that the system will still come up, making it easier for you to
restore from backup as necessary.
</quote>

In addition, there are some security implications - you cannot hard-link 
across filesystems (well not last time I tried anyway...).

Finally, I use everything in / for my workstation, but am reconsidering 
after a runaway file writing process filled up everything and panicked 
the box - I am guessing that if I had a separate /home (say), the that 
would not have happened!

Cheers

Mark