Flash drive hidden under the carpet and connected via a USB extension, holding the decryption keys - threat model is a robber making off with the hard drives and gear, where the data just needs to be useless or inaccessible to others.
There’s a script in the initramfs which looks for the flash drive, and passes the decryption key on it to cryptsetup, which then kicks off the rest of the boot mounting the filesystems underneath the luks
I could technically remove the flash drive after boot as the system is on a UPS, but I like the ability to reboot remotely without too much hassle.
What I’d like to do in future would be to implement something more robust with a hardware device requiring 2FA. I’m not familiar with low level hardware security at all though, so the current setup will do fine for the time being!
Dang, that thing is the bees knees!
Would make more sense to replace just the batteries rather than the whole unit IMO. Looks like it takes standard 12v 7Ah sealed lead acid batteries, so should be doable for under $120 (if you buy them individually and use the existing battery harness)
I have three other UPSes, but none of them are as good as yours lol:
Edit: fix bullet list formatting