Before you scream at your screen, I am aware this setup isn’t ideal, to say the least, my Self-hosting has been composed of a laptop with a usb carry with a 2.5 1tb hard drive. I recent made up my mind about getting a couple 4 tb server hdd (heard barracuda are relatively silent) to run software raid 1, since I can’t find a budget double bay carry (that I can purchase locally) I’ve decided I’ll get a couple 3.5 inch usb cases and get a splitter to run the power from just just one brick.
My question is regarding resiliency, I get occasional blackouts and low tension every now and then, a few times a year but it can be a few times in a day. I’ve never had hardware dying because of it and I don’t have a UPS, but I worry I could be risking data corruption or something swapping to this setup because of the extra power those drives will need being fed from the wall instead of the laptop (the laptop feeds the current drive over usb alone and it has a battery) which could be abruptly cut off every now and then. Right now, the worst this has caused has been having ro reboot the system because it got unmounted but never had a loss of data from this.
Am I worrying for nothing? Would it be just the same? Should I just put this off until (if) I can afford the drives plus a ups? So far I’ve had my server for basically free, but I’m running out of space for family photos and I kinda have to upgrade.
Yes when it comes to RAID, a UPS is a must.
Linux MDADM is not resiliency against power lose. And will overwrite from master if they are not equal.
Cow system ZFS, LVM, BTRFS and similar, have separate metadata table to compare against. But even then they can be affected by write hole in the event of a powerloss.
If you are thinking it for “backup” for redundancy in case of disc error, a solution can be to use something like borg backup, and a source disk as a BTRFS file system so you can be notified if there is checksum errors.
A cheap UPS is 60€, it will work good enough.