Hello, first-time Unraid user here. Here's my machine at a glance:

• Unraid 7.2.2

• Beelink ME Mini NAS

• two 4TB WD Red SN700 NVMe drives

  • both passed MemTest86

  • both passed SMART test

• one 2TB Crucial NVMe

  • same as above

I've been slowly configuring my home network over the past few months, yesterday finally got around to actually mounting my NVMes and ran into a problem. The 2TB drive mounted fine, but the 4TB in a ZFS mirror pool return the error "Unmountable: wrong or no file system".

I tried troubleshooting through Gemini 3, but got nowhere. I erased the formatted partition a handful of times, rebooted the router, a few other things, but still getting the same error.

I thought maybe the NAS's slot arrangement was the problem--slot 4 in the NAS has faster read/write than the other slots--so I took the drive in that slot out and put it in a standard-speed slot, but the mounting error remains.

Does anybody have any idea what might be going on? The drives seem to be healthy, of course they're both still under warranty, but I wonder if I've just configured something wrong that's causing them to return an error.

If I understand correctly, this is a new pool? If yes, please post the diagnostics after a format attempt; if it's an existing pool with data, just post the diags.

Thank you for the help🙇‍♂️

Yes, this was a new pool on a new NAS. The 2TB NVMe is in a pool by itself, and the two 4TB ones are in a ZFS mirror pool.

I've attached the diagnostics zip file, is that standard? I can post the code here if that's best practice.

I also have the SMART test reports for the 4TB NVME drives if that would be useful.

tower-diagnostics-20251129-2212.zip

Nov 29 20:09:06 Tower root: cannot create 'mirroralpha': name is reserved

mirror is a reserved name by ZFS, it cannot be used even as a pool name, or at the start of a pool name. Change the pool name, and it should then work, alphamirror for example, would be OK

Heavens to betsy, that worked😩

Thank you very much, sir.