Creating Read Only Debian Install

Hi,

I'm running Debian Etch from a Compact Flash card, on a Soekris 5501. Now this box will be installed on a remote site, with no UPS  protection, and no on site support. To minimise the chance of file system corruption when the unexpected happens, I want to make the root partition read only, then create a /rw partitiion which will contain the various files that the OS needs rw access to.

We are running the absolute minimum install, not running any mail servers, dns, firewalls or anything like that. We just have our own custom app on there that has very simple needs.

I have the above setup working pretty much, although before I install this on the remote site, I want to make sure there is nothing I'm missing as I pretty much guessed which files need to be writable.

I have simply moved the following directories to my /rw partition, and done a ln -s to create the symbolic links in their place

/etc/adjtime
/etc/issue
/etc/issue.net
/etc/network/run
/etc/resolv.conf
/root
/tmp
/var/lib/logrotate
/var/lock
/var/log
/var/mail
/var/run
/var/spool
/var/tmp

My /etc/fstab looks like this:

proc            /proc           proc    defaults        0       0
/dev/hda1       /               ext3    defaults,ro 0       1
/dev/hda2       /rw             ext3    defaults        0       2
/dev/hda3       none            swap    sw              0       0

And in order to remount / a rw when required I'm executing:

mount -o remount,rw /

One thing I don't understand, is when I mount  / a read only my /rw partition disappears when I run df to check partition usage?

So really after some validation as to if my above approach is correct and if there is anything I have missed?


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