[wjdp]

A NAS built from generic x86 hardware and some disks. Use ZFS, it's a bit of a rabbit hole but an excellent choice for both reliability/redundancy and as a tool to backup. I'm not gonna explain how this works, just describe what you can do, it's an option.

ZFS:

- ensures you don't get bit rot

- manages both disks (raid/mirrors &c) and the filesystem, it's an all-in-one solution

- supports block level replication to local and remote systems, after the first backup it's fast

- can create dynamic partitions to group files together and build replication strategies around

Choose either RAID or mirrored drives (https://jrs-s.net/2015/02/06/zfs-you-should-use-mirror-vdevs...) I've gone mirrored but more for flexibility and performance. Use a calculator to see what options of disks you have https://jro.io/capacity/ (and google 'ZFS calculator' for others)

For backup get a second machine somewhere else in your house with a smaller setup and use ZFS replication to keep it up to date with everything on the main box you need backed up. Currently I use a raspberry pi with a USB disk but this is perhaps cutting it fine. You wanna keep this online so ZFS can periodically check the health of the data on the disks. Fully offline backups can be a risk.

Finally for a 3rd backup use some of those external drives, format to ZFS and use replication. Plug them in on a schedule and take a backup.

If you want to backup to remote systems (cloud/a box in your parents house) it also supports filesystem encryption. With the right options you can stream incremental backups over SSH only passing encrypted blocks. The system at the other end never needs to see the raw data.

[silverquiet]

I think this is spot on, and the only thing I'd add is to use something that can take ECC RAM. Rather unfortunately, that probably means server hardware which doesn't always mix great with consumer settings. I'm currently thinking about a Dell Precision workstation for this as it seems like a decent blend of server hardware in a nice, quiet package.