Adding a new drive / fstab

[V. Alex Brennen]

Many people said to just "use what works for you."  I agree.  There's no
deep need to conform to the POSIX HFS standard.  Especially, since many
of the points in the standard come from negotiation with the makers of
flavors of UNIX which are now long dead or dying.  If you look at the
LSB equivalent of the HFS standard, you can see it is much less verbose
and allows much more freedom for the administrator.

Regarding creating an additional mount point in the root directory,
which was also suggested, there are reasons why you may not want to do
that.

The reason that many people avoid putting anything under '/' that is not
created by the operating system itself is that if you have any type of
problem mounting the disk space that you plan to use under that
directory, your programs or system can fill the '/' partition (either
its available blocks or its available inodes).  On some systems, this
can cause booting and operational problems with your server bringing
some or all of your service down.  Linux has become somewhat resistant
to these types of problems.  It is much more so than the older *NIX
Operating Systems.  But, on Linux you would still encounter some
problems.  Depending on how your OS Disk(s) are partitioned, those
problems could be very serious.

This issue with filling up disk partitions for which parts of your core
operating system are depending on being able to write to has been
written about extensively.  The majority of the content on the web comes
from security sites and deals with including /var (and
especially /var/log) on a partition that can be filled by an individual
who has access to your system with only basic user permissions.  For
example, having /var on the same disk partition as /home and not having
quota restrictions in place.  Additional content can be found regarding
what will happen to applications if application/service critical
directories such as /tmp, /var/tmp, /var/spool/mail, /var/postgres,
etc., can easily be filled by even a non-malicious user.

Many default disk partitioning plans, including those of RedHat and many
others, create a very small '/' partition.  So, it can quickly be filled
before you even notice that you've had a problem.  Some distributions
will also not properly separate critical portions of the file system
onto independent partitions (such as /var and /home).  So, I'd recommend
that while you should do what ever works for you, it would also be good
to think about what could possibly go wrong.

I've run into problems myself before on Gentoo by not creating a
separate partition for /afs and then having an AFS boot sequence fail
because the local AFS service was having problems.  I then, stupidly,
had the same problem some time later on a RH system by not creating a
separate LV for /mnt and then having a SAN array mount failure during
boot.


          - VAB
-
V. Alex Brennen       vab at mit.edu
Senior UNIX Systems Administrator
MIT Libraries   E25-131   x3-9327
       http://vab.mit.edu/