controlling whether installer ISOs automatically format other disks (for PCAP storage, data store, etc.)

[mmguero]

I'm opening this discussion from an email that was sent to the project as I'd like to have it here for the record. I've also opened idaholab#529 as an enhancement idea that came from the discussion.

As indicated in the documentation, Malcolm's installer ISO assumes all drives attached to the system are available to it for formatting and use, and this is pretty much automatic and baked-in to the ISO installer.

During the installation itself, this script determines the disk onto which Malcolm will be installed, and uses these rules (depending on the type of installation chosen) to partition that disk.

Then, at the end of the installation, the preseed creates a file called /etc/capture_storage_format which is detected on first boot and used to format the other non-system drives (for PCAP storage, database, etc.). The script that actually does that formatting is found at os-disk-config.py.

My suggestion for now (until idaholab#529 is implemented) is, if you don't want os-disk-config.py to format other disks, is to prevent that from happening completely rather than trying to modify the contents of os-disk-config.py. To do that, at the end of the ISO installer's installation process when it's asking you the final questions (like Disable IPv6?, etc.), I would open another console by hitting Alt+F2, then hitting Enter to drop into a prompt. Run the command rm /target/etc/capture_storage_format to remove that file. Then hit Alt+F1 to return and finish the installation. Upon first boot the other drives would then remain unformatted. If you wanted to format them yourself, you could do so of course using parted or gparted or something like that.

Alternately, If you'd like more control over the system you're running Malcolm on, perhaps installing Malcolm using the docker-based installation (as in this example, or this video) would fit your needs better.

[mmguero]

Marking as answered, since I'm really just talking to myself here anyway.