Hi all,

I ran into a critical issue right after updating Unraid to 7.1.4:

- I had a dedicated second encrypted ZFS pool (`nvmepool`) that I used exclusively for sepperate appdata.

- This pool hosted 2x MariaDB databases for both Nextcloud and WordPress.

- After the update, the entire pool is basically empty – only a few MB used, all previous appdata (including the DB directories) is gone.

- No ZFS snapshots were enabled.

- I do have CA Appdata Backup archives, but unfortunately they don’t include the MariaDB data itself, only the container templates.

What I’ve checked so far:

- `zpool status` → pool is ONLINE, mirror healthy, no errors.

- `zfs list` → only tiny, freshly created datasets, none of the old ones remain.

- `zdb -l` on the devices returns only “failed to unpack label”.

- Searching the pool for `ibdata1` or `.ibd` files yields nothing.

So it really looks like the Unraid update either reinitialized or completely wiped the ZFS pool contents, and all databases are gone.

**Questions:**

- Has anyone experienced something similar – a separate ZFS pool used for appdata being wiped after an Unraid update?

- Are there any realistic recovery options, like `zpool import -T` (older TXG) or using tools like `zfs_recover`?

- Has anyone successfully recovered MariaDB data (ibdata1/ibd files) from a ZFS pool without snapshots?

Any insights, experiences, or even confirmation that I’m out of luck would be really appreciated. These databases contained a lot of work (WordPress + Nextcloud).

Thanks 🙏

Edited September 19, 2025Sep 19 by t0mi

okay after investigation i found out i pointed the mariadb config and data folders to /mnt/nvme and not /mnt/nvmepool so files were written in RAM, yeah i never rebootet... after update all gone... this was a stupid mistake because the backup script only backup'd the normal /mnt/user/appdata and /mnt/nvmepool/appdata