Add ability to test pool recovery

README.md

@@ -95,4 +95,42 @@ sudo zdb -l /dev/sdX
 ```
 
 `wipefs --no-act` reports signatures without modifying the device. `zdb -l`
-should not find a readable ZFS label after a successful run.
+should not find a readable ZFS label after a successful run.
+
+## Recovery Assessment
+
+`verify-zpool-recovery.sh` checks whether ZFS can find and rewind an exported
+or faulted pool. It cannot restore labels that have been completely overwritten
+by the eraser, so recovery after a successful erase is unlikely. Use it before
+erasing a device, or when ZFS still detects at least part of the pool metadata.
+
+List pools ZFS can discover without modifying anything:
+
+```bash
+sudo ./verify-zpool-recovery.sh
+```
+
+Check whether a specific pool can be recovered with a transaction rewind. This
+uses `zpool import -nF`, which is a dry run:
+
+```bash
+sudo ./verify-zpool-recovery.sh tank
+```
+
+If vdevs must be found in a non-default directory, supply it explicitly:
+
+```bash
+sudo ./verify-zpool-recovery.sh --directory /dev/disk/by-id tank
+```
+
+After reviewing the dry-run output, attempt the import with rewind recovery:
+
+```bash
+sudo ./verify-zpool-recovery.sh --apply tank
+```
+
+`--apply` runs `zpool import -N -F`: `-F` may discard the most recent
+transaction groups, and `-N` imports the pool without mounting datasets. The
+script requires the exact confirmation `RECOVER tank` before issuing that
+command. Inspect the result with `zpool status tank` before mounting datasets
+or performing any further changes.