I'm wondering if it is possible to run a Linux server from a read only disk, specifically CentOS 5.4.
Our system has a number of Linux machines each with their own disk with it's OS installed. Everything is read/write enabled at the moment. We're booting from these disks but running all our software that we develop on some external disks shared over NFS.
What we want to be able to do is ensure that nothing is ever written to the internal disk with the OS on it, only to the external drive shared through NFS. I'm thinking we can probably manage this by editing the /etc/fstab file and mounting the drive as read only.
So if we took an image of the internal disk then booted the system, ran our software (which would only touch the external disks), then shut down the system and took another image of the internal disk there wouldn't be a single byte different.
The OS itself is going to want to write its own log files etc so I can't see that mounting the drives as read only would result in a functioning operating system - or would it?
I can only think some kind of network boot would achieve this, but there is zero possibility of adding an extra machine to act as a DHCP and TFTP server for this.
Any help or ideas would be much appreciated! :)