Hello,

I've been lately thinking about my backup strategy as I'm finalising building my NAS. I want to use ZFS and my idea was to have two drives in mirror (RAID-1) configuration and just execute periodical snapshots on such dataset. I want to the same thing in a second location, so in the end my files would be on 4 different drives in 2 different locations and protected by snapshots from deletion or any other unwanted modification.

Would be possible with this setup to just swap one of the drives in one location and have ZFS automatically rebuild data on the new drive and then I take the drive to second location and do the same so all drives would be exactly the same, instead of copying data manually? Though I believe all of the drives would need to be exactly the same size, is that right?

Is it a good idea in general or should I ditch it, or maybe just ditch the part with ZFS rebuilding and use instead some kind of software for that?

Thank you for your help in advance!