Hi everyone,

I followed this guide 'How can I remove a subpool from a zfs pool using Unraid v7.0?' in https://forums.unraid.net/topic/46802-faq-for-unraid-v6/ to remove my slog mirror. After I started the array I got the error "Unmountable: unsupported or no file system". It only gives me the option to format the drives. If I stop the array again I can import the zfs pool manually and list the datasets, so I guess and I hope my data is still existing.
What should I do?

unraid-server-diagnostics-20260209-1754.zip

Pool also has an L2ARC vdev, so it must be assigned together with the other devices during import:

Feb 9 17:54:02 Unraid-Server emhttpd: config:

Feb 9 17:54:02 Unraid-Server emhttpd: #011NAME STATE READ WRITE CKSUM

Feb 9 17:54:02 Unraid-Server emhttpd: #011stronghold ONLINE 0 0 0

Feb 9 17:54:02 Unraid-Server emhttpd: #011 raidz2-0 ONLINE 0 0 0

Feb 9 17:54:02 Unraid-Server emhttpd: #011 /dev/sdi1 ONLINE 0 0 0

Feb 9 17:54:02 Unraid-Server emhttpd: #011 /dev/sdh1 ONLINE 0 0 0

Feb 9 17:54:02 Unraid-Server emhttpd: #011 /dev/sdg1 ONLINE 0 0 0

Feb 9 17:54:02 Unraid-Server emhttpd: #011 /dev/sdm1 ONLINE 0 0 0

Feb 9 17:54:02 Unraid-Server emhttpd: #011 /dev/sdk1 ONLINE 0 0 0

Feb 9 17:54:02 Unraid-Server emhttpd: #011 /dev/sdj1 ONLINE 0 0 0

Feb 9 17:54:02 Unraid-Server emhttpd: #011cache

Feb 9 17:54:02 Unraid-Server emhttpd: #011 /dev/nvme0n1p1 ONLINE 0 0 0

So I would create a new pool with 7 devices instead of 6?

Correct, all together, not as a subpool for the 7th device.

Thank you so much — you saved me there! Maybe consider adding a small note to the FAQ mentioning that all remaining devices need to be included, not just the vdev ones (that part tripped me up).