I think using 1 disk redundancy is a mistake. It’s not only physical failure you’re worried about, it’s an error upon rebuild when you lose a drive. Bit rot on

I think using 1 disk redundancy is a mistake. It’s not only physical failure you’re worried about, it’s an error upon rebuild when you lose a drive. Bit rot on your remaining drives can occur which wouldn’t be detected until rebuild time when you lose a drive, and that could cause you to lose your entire volume. Bit rot can be checked for but you can’t always be sure and with larger and larger sets of data it gets slower to do. I use raid 6 and also backup my data externally to another nas as well as backup to a static usb drive. Backup requires multiple different types since failures are so catastrophic and can occur in ways you don’t expect.