Hello.
I have some questions related with the layout of the filesystems
on OpenBSD and hope someone will be able to help me. I must start
saying that I never had problems with this setup, but I certainly
would appreciate some advice on it. To make things clear, I will
try to outline the output of /etc/fstab, disklabel and df on a table:
-----------------------------------------
Mounted on Type Size bsize fsize
- ---------- ---- ------ ----- -----
a / ffs 64 MB 16384 2048
b swap swap 512 MB N/A N/A
c <all the disk>
d /altroot ffs 64 MB 16384 2048
e /var ffs 25 MB 16384 2048
f /usr ffs 768 MB 16384 2048
g /var/log ffs 16 MB 16384 2048
h /var/mail ffs 128 MB 16384 2048
/var/run mfs 4 MB
i /var/tmp ffs 24 MB 16384 2048
j /var/www ffs 32 MB 16384 2048
k /usr/X11R6 ffs 256 MB 16384 2048
l /usr/local ffs 2048 MB 16384 2048
m /usr/obj ffs 896 MB 16384 2048
n /usr/ports ffs 512 MB 4096 512
o /usr/src ffs 1024 MB 8192 1024
p /home ffs + MB 16384 2048
/tmp mfs 64 MB
It is, approximately, the layout of all my systems. Not all computers
have the same filesystems structure. For example, servers (currently
a Soekris net4801 and a Dell PowerEdge 350) do not run X, nor have
/usr/X11R6 on it. I do not extract the contents of XF4.tar.gz on any
of my systems (workstations or servers) either.
There are no filesystems with more than 50% space used and, to avoid
running out of inodes, /usr/ports and /usr/src have no default block
and fragment sizes either.
My questions are:
1. /var/run and /tmp are memory filesystems right now. (/tmp does
not need to survive to reboots and the contents of /var/run
are better going away when the machines are restarted.) Both
have entries on /etc/fstab with the SAME BLOCK SPECIAL DEVICE
(/dev/wd0b). Is it a good practice?
2. Are the sizes of the filesystems right ones? I am thinking on
- "/var" (on the installation booklet provided with the OS
it is recommended a size of 200 MB for this filesystem,
I *never* found a /var filesystem larger than 10-20 MB).
Can it really be so large?
- "/usr/obj" (what is the maximum size required for making
a full operating system rebuild?) I will certainly not
do a full rebuild, only apply some patches, but it is
better to know. Today, storage space is cheap and we
can afford a 900 MB filesystem... my current estimation
comes from some "make world" on NetBSD... it would be
nice to know the amount of space that is required.
Can we use the default block/fragment sizes on it?
- "/usr/ports" (is 512 MB enough for it?) I usually stay
at binary packages, but sometimes I need to build software
from source and would like to know the recommended space
for this filesystem.
I know that some filesystems (e.g., /var/mail and /var/www) are
too small for most uses, but the size of these filesystems is
very easy to know once we know how a computer will be used.
On these machines I do not need a large /var/mail (only one
of these machines receive standard email -not system reports-
and it is stored in /home as soon as I run the inc(1) command
in nmh.) Others (e.g., /usr, /usr/X11R6, /, /altroot -that is
a dump of the root filesystem automatically done-) do not
grow at all.
3. Any though about the filesystem layout? I know that it is
certainly complex, but worked nicely for me in the last years.
All these filesystems (except /var/tmp) are recommended in
the documentation and, as I said, I do not remember any of
these filesystem growing up to 60% in either space or inodes
usage in the last years... but I never did a full rebuild
of the operating system nor installed large packages from
source code (mwm is soo nice, and it comes in the official
CD-ROMs!)
...I do not need a large /usr/local either. I just install mwm,
firefox, nmh and a LaTeX distribution. Most utilities I need come
with the operating system (nearly all, and for making figures I like
MetaPost that comes with the LaTeX distribution.) No problem at all
with these filesystems: its size is highly site dependent, but very
easy to work out for me. As I said, I usually do not install third
party applications.
Thanks a lot for reading this post.
Igor.
