Hi, currently I have a almost none backups and I want to change them. I have a PC with Nextcloud on 500gb ssd that I also use for gaming (1tb system drive). Nextcloud would be used to store/sync images, documents, contacts, and calendar from my phone and laptop. I also have an old pc that has 2x 80gb, 120gb, 320gb, and 500gb hdd. I want to use it for other backups like OS snapshots, programming projects, etc. but its not a big hdd but a lot of small hdds. Should I store each backup on 2 drives? Can I automate this? Any suggestions would be helpful.
Yes.
I believe it really depends on the amount of data you write to the disks. From my experience: if you’ve two disks, same model, same brand, same powered on hours they might fail at the same time and you end up with nothing thus for most people it might not even be worth to RAID at all on a home NAS. Have a main disk for always online to write / read from and a second disk that is turned on once a day to rsync all data is. Most likely safer and more reliable, you also get extra protection against accidental deletes.
These kinds of issues are what drove me to use RaidZ2 (I went over board with using 6-disks): When during resilvering after a broken disk a second disk fails, it’ll still keep the data.