I have a separate thread open around this, but no responses yet 
In Cockpit ZFS, don’t forget to change the disk identifier from the default “Alias” option to one of the others. Drives will still show up in the disks section even when no alias exists and cockpit throws an error. I think used device or disk id (can’t remember the exact verbiage) to add a nvme as a cache drive.
2 Likes