I do fieldwork with a number of computers running ubuntu performing critical tasks doing fieldwork. The computers are similarly configured with slight variations.

Since we've had some configuration issues in the past, my boss is pressing for us to take an image of the installation on each computer, and restore each computer to that image before they are to go into the field.

My preferred solution would be to write a common script that checks to ensure that the configuration of the system is correct and that the system is operational. If the computer has been verified, isn't restoring it to that configuration redundant? And are there any inherent problems with doing so?

My reluctance stems from the fact that our software and configuration is subject to change in the field, but these changes must be made across all the computers. That means that when a change is made, all the restoration images have to be updated as well. The differences in the configuration of each of the computers live in /etc. In the event that restoration is required, I would prefer to keep a single image containing everything that is common to all machines, and have a snapshot of each computer's /etc directory to be used for restoring the state of that particular machine.

What's the better approach?