I'm currently traveling for months at a time and my homelab has become unreachable to me over VPN due to a unknown complication after a power outage.
Just as a learning experience for all, my mistake was that I set-up my VPN very far down the stack - as a wg-easy app inside TrueNAS SCALE's apps ecosystem. My very important reason for doing it was that way was that wg-easy allows for setting up client devices with a QR code...
Anyway, the NAS is not booting back up nor do the TrueNAS apps. I should've set my VPN up right at the front of the network - on my MikroTik router that also supports Wireguard. The funny thing is I was so happy that my NAS has IPMI and whatnot but now I can't even access it.
For now the NAS is kept powered on from what I know, it just doesn't boot. This should help prevent bitrot until I'm back. All important files are backed up on a 3rd party service.
It's a shame my Jellyfin and Navidrome inaccessible, but I'll live.
Now I'm thinking about buying an UPS so that this doesn't happen in the future. I'd like the UPS to be fanless and rackmount, so that limits me to ~700VA territory.
Devices in my homelab pull about 65W idle and spike to say 150W when everything is booting. ISP modem, router, POE+ switch, AP, NAS. I might add another 20W due to a Lenovo M920q in the future.
I only really care about NUT and graceful shutdown instead of long runtime on battery.
I was thinking about this: https://www.apc.com/us/en/product/SMT750RMI2U/
In my country I can get it with new batteries (no front panel) and a network card for NUT for a total of 180 EUR.
Would that work? Would you be afraid of leaving an UPS (it is kinda like a bomb after all) unattended an leaving your home for 6 months at a time?
UPDATE: Turned out that the culprit of the downtime was my switch - the D-Link DGS-1210-10P rev. B1.
The way the management web interface of the switch works is pretty unintuitive. Namely, if you change some settings in the web interface and hit save in one of the sections, the settings are saved in the volatile memory of the switch. This basically means that the settings are only saved in RAM, which is cleared on power loss. To save the settings into non-volatile memory which persists on reboots, you need to find the "Save" section at the top of the UI. This is described here: https://networkengineering.stackexchange.com/questions/20158/dlink-switch-loses-configuration-on-power-off
So basically, my problem was that the settings weren't commied to nonvolatile memory and on a short 1 minute power loss the switch restarted.
I got an UPS anyway now, SMT750RMI2U