What is the most reliable option for longetivity?
i was looking at the wd ae, which they claim is fit for this purpose, but knowing nothing about hard drives, I wouldnt know if it was a marketing claim..
I have a couple of 8TB Seagate SMR drives. They’re slow as sin but perfect for cold storage backups.
One sits in a safe deposit box and the other is in my backup server and gets zfs snapshots replicated to it automatically with sanoid. I swap them out about every six months. My data is very safe.
Main server zfs array with snapshots replicated hourly to backup zfs server, replicated weekly to HD swapped in SD box every 6 months.
Snapshots on the file system are instant and can be rolled back or opened in read only mode if you need an older version of the file.
Sending a snapshot through replication is also much faster as the system just sends the snapshot itself which updates the files system in one pass by sending all of the changes made rather than having to compare file by file.
For comparison, using rsync to update my backup with 250,000 files might take 20-30 minutes because it has to check every file on the source and destination to see if it has been modified. Sending a zfs snapshot is 15 seconds because it just sends the differences in one pass.