3-2-1 is some basic knowledge, even though I’ve been guilty of not doing that in the past when the budget was tight. But at least in those cases I’d take as many old PCs as I could find and run backups on them.
COW filesystems like BTRFS/ZFS with btrbk/sanoid are great for this. Only the initial copy may take a while, but after that it only takes the delta between the source and the destination to synchronize. On my main Server I have the OS on a single drive with BTRFS and all the actual data lives on a 4 disk zpool in raidz2. I have cron jobs set up to do hourly snapshots on both and I keep about a week worth of history. The BTRFS one gets synced to an external drive every 24 hours, while the zpool gets synced to another external 4 disk zpool on a weekly basis.
3-2-1 is some basic knowledge, even though I’ve been guilty of not doing that in the past when the budget was tight. But at least in those cases I’d take as many old PCs as I could find and run backups on them.
COW filesystems like BTRFS/ZFS with btrbk/sanoid are great for this. Only the initial copy may take a while, but after that it only takes the delta between the source and the destination to synchronize. On my main Server I have the OS on a single drive with BTRFS and all the actual data lives on a 4 disk zpool in raidz2. I have cron jobs set up to do hourly snapshots on both and I keep about a week worth of history. The BTRFS one gets synced to an external drive every 24 hours, while the zpool gets synced to another external 4 disk zpool on a weekly basis.