Hacker News new | ask | show | jobs
by havernator 1885 days ago
Can you? I was under the impression that without an “export” beforehand, you can’t.
3 comments

See the "split" command with OpenZFS 0.8.0+:

* https://utcc.utoronto.ca/~cks/space/blog/linux/ZFSSplitPoolE...

Only with mirrored drives.

Any RAID-Z level would need a full export/import as data is striped, but hot-swap drives can be pulled once things are unmount.

I recently did just this. I had to use the -f flag but it imported just fine on a different computer.

I agree that it can be a bit daunting to operate, there are a few footguns around that, while it might not lead to data loss, but can lead to unfortunate situations.

Just the other day someone on the mailing list had managed to add a single drive as a new top-level vdev to a petabyte pool, rather than adding it as a new spare drive, simply by omitting the word "spare" from the "zpool add" command...

That said, I've been using ZFS at home here with 6+ disks for almost a decade now, and I've never lost data despite lots of various incidents, including lots of power losses and various hardware failures (like disks, mobo and PSU). So overall I'm very happy with it.

I guess it just seems like there’s a lot more state than with file systems I’m used to dealing with. In fact, since journaling became normal, most just have two states (from the user’s perspective) whether powered on or off, mounted or unmounted, whatever—broken, or OK.

ZFS has... a lot more. It’s just very different and the way these states fit together, and worrying about how to operate on them safely, makes me more nervous, in many ways, than less-safe file systems do. I’m sure that will pass, but it’s still not fun.

Yeah since it replaces "the whole stack" it's daunting and a lot of terms to, well, come to terms with.

For me I found it beneficial to watch the videos on how ZFS is built up, like this one[1]. Helped putting the pieces together.

[1]: https://www.youtube.com/watch?v=MsY-BafQgj4

Oh no that'd be a terrible design:) AFAIK the most difficulty is that you might have to use `zpool import -f` to force it to ignore the pool not having been cleanly exported.

EDIT: It'd look like this: https://serverfault.com/questions/964075/how-can-i-recover-m...