TL;DR

Pool will not import after power loss: zpool import -f, then -F if you must rewind txgs, then zpool scrub.

After a power cut the pool is often still on the disks but zpool status is empty: it was left dirty-exported, or the host booted without it. Do not zpool create on those disks.

See what is there

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zpool import

Lists importable pools by name (VOL1 below) and whether they are FAULTED / UNAVAIL.

Import

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zpool import -f VOL1

-f means “I know it might still look imported elsewhere”. That is the usual crash case: ZFS thinks the other side still holds it.

If -f is not enough because the last txgs were half-written:

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zpool import -F VOL1

-F rewinds to an earlier consistent txg. You can lose the last seconds of writes. That is better than a pool that will not mount.

Dry-run:

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zpool import -F -n VOL1

Afterwards: scrub

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zpool scrub VOL1
zpool status VOL1

Scrub confirms the rewind did not leave checksum errors. Let it finish before you delete “just in case” snapshots.

Do not

  • zpool create on the same sdX devices wipes the labels.
  • -F is not the first knob: try -f first.
  • If the pool is the root (rpool / Proxmox bpool), import from live media, not from the system that will not boot.

See also: replacing disks, basic commands.