If you keep a ZFS mirror of the most-recent N drives, and store them separately, that should be pretty good.
I forget how ZFS behaves if a mirror is missing drives though, if some are off-site. Hopefully it's smart enough to let you do that and just rotate through.
You’d have better luck making a full (manual) copy most likely (ZFS send/recv, or mirror then un-mirror even better), assuming you’d run a scrub after.
Or manually make checksum files I guess. I’ve done that, less ‘magic’ that way.
The purpose and benefit of a zfs mirror is that every disk in the mirror contains everything. So it's expensive in space usage, but great for reliability. As long as any one of the disks in a mirror survives, you can recover everything.
If you offline or detach the drive, it should be fine afaik. Detach is probably the better way to go though, because it removes the drive from the status listing.
You can’t ZFS import a pool on a drive detached this way without things happening to that drive, is the issue. So if you want a point in time archive, it’s dangerous to do that.
I think it’s nearly impossible
to actually ZFS import a pool from just a single detached drive too if the original is nuked, but I imagine there is some special magic operation that might make it possible.
Splitting the new disk off into it’s own pool doesn’t have any of these issues, and is a much cleaner way to handle it.
Also, run zpool scrub regularly to detect and repair any corruption early.
If you keep a ZFS mirror of the most-recent N drives, and store them separately, that should be pretty good.
I forget how ZFS behaves if a mirror is missing drives though, if some are off-site. Hopefully it's smart enough to let you do that and just rotate through.
ZFS doesn’t handle that well generally.
You’d have better luck making a full (manual) copy most likely (ZFS send/recv, or mirror then un-mirror even better), assuming you’d run a scrub after.
Or manually make checksum files I guess. I’ve done that, less ‘magic’ that way.
> ZFS doesn’t handle that well generally.
Can you expand on that?
The purpose and benefit of a zfs mirror is that every disk in the mirror contains everything. So it's expensive in space usage, but great for reliability. As long as any one of the disks in a mirror survives, you can recover everything.
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If you offline or detach the drive, it should be fine afaik. Detach is probably the better way to go though, because it removes the drive from the status listing.
You can’t ZFS import a pool on a drive detached this way without things happening to that drive, is the issue. So if you want a point in time archive, it’s dangerous to do that.
I think it’s nearly impossible to actually ZFS import a pool from just a single detached drive too if the original is nuked, but I imagine there is some special magic operation that might make it possible.
Splitting the new disk off into it’s own pool doesn’t have any of these issues, and is a much cleaner way to handle it.