Hello everyone, I've been an Unraid user for several years now, and everything has been running flawlessly until today, when I encountered what seems to be a serious issue.

Earlier today, I suddenly received a notification that my array had stopped. Upon checking the interface, I saw the dreaded "No Device" error associated with one of my data disks

• I restarted the system, but the error persists.

• I have not started the array since the initial stop, as I prefer to wait for your advice.

• There were no power outages or issues at home, so I don't believe power is the root cause.

• I'm attaching my diagnostics file (I regret that I generated it after the system restart, but I hope it still contains useful information).

Could the disk have simply failed after several years of service?

What is the likely cause of the "No Device" error (controller issue, cable, or the disk itself)? Is it safe to start the array without this disk (assuming it's failed) so I can continue using the server and eventually replace it?

Any guidance would be greatly appreciated! Thank you in advance for your help.

vault-diagnostics-20251207-1524.zip

Ok I disconnected and connected power and sata and started server again and nothing changed. Unfortunately I heard some strange clicking, like sth wanted to start but couldn't, so I disconnected this disk from power and started server again and didn't hear this sound. It was definitely from this disk. Also wife told me that during day was some power drop, for like less a sec, so now I think it was because of that. I assume disk is dead ye? How long can I run without this disk? I think for the new one I have to wait until new year.

15 hours ago, Zeuskk said:

How long can I run without this disk?

There's no time limit, just be aware that if another disk fails, you will likely lose data.