So my NAS decided overnight to become unavailable. Doesnt sho up on my router table or using LanScan. I've done all the usual cbales, sockets etc and they are all fine. Moved it to my study and booted into the unraid "bios" terminal window. Lots of checksum and critical medium errors on sda (presumably my USB boot drive). Then it suddenly decided to work. Appeared on the network and I could access it on my TV. So I moved it back upstairs where it lives and it stopped working on reboot. Back down again and it booted ok so did a reboot and it stopped again.

I suspect either a corrupt file on the USB OS or even a faulty sector on the USB flash drive. Should I try a reformat ? And if so how do I recover a backup from the ssd installed ? Assuming I can get the NAS to boot up again

Or should I just buy a new flash drive and start again. My disks and media files are OK I assume but I do have backups

Edited December 16, 2025Dec 16 by 1topgazza

I reformatted the USB and copied back the files to it but still no joy. I now get bzfirmware checksum error. Not sure what to do next so any help appreciated.

I paid for a licence but it has expired so do I need to buy another ? Or I'm supposed to have a backup on the ssd I installed but of course no way of accessing it now. Help !

Edited December 14, 2025Dec 14 by 1topgazza

9 hours ago, 1topgazza said:

I now get bzfirmware checksum error.

Start by running memtest.

I must have had a dumb moment. Of course, checksum usually equals memory. It was late mind you. I’ll do that.

I’ve actually started a rebuild with fresh Unraid 7.2.2 and I’m quite happy to do that. But metes will be run… DOH!

11 hours ago, 1topgazza said:

I paid for a licence but it has expired so do I need to buy another ?

If you have no backup then you should be able to get a copy of your licence file reset to you if you contact support.

You say you have a paid for 'expired' licence so by that I assume that you are on the new licence model and your free year of upgrades has expired? If so any licence file that support sends you will only be valid for the release that was the stable release at the point the expiry happened - you would have to pay for another year of upgrades if you want to move onto a later Unraid release.

Mem tests ran for an hour with no issues. Since reloading the OS the NAS has been stable. Just need to sit down and reconfigure. All my media is still on the disks of course, I do have full backups but I'm hoping I can use the config files from my copy of the USB OS flash drive.

Regarding licence. I can't remember was version i was on but my original licence expired in May 2025. But loading 7.2.2 from Unraid's website prompted me to use my original licence. But in any case it's all working in that respect and I was very impressed by how straightforward it was.

Is it OK to continue with related questions ? Correct if its not and i'll raise another post. And a huge thank you for the help to everyone. I'm learning Unraid and its a steep curve.....

I have the following. A fully restored Unraid OS. It shows my 4 x 8TB drives, my USB OS flash drive and my SSD which I use for cache. The array is not running so the 8TB drives and SSD just show as a list of drives. All the hardware remains the same including the USB Flash and the USB OS licence is recovered from my account so presumably still tied to the USB ID. No containers/dockers or apps such as Plex downloaded. So its a pretty bare bones install

Given the above if I copy the config file from my USB backup to the NAS USB will it set everything up where it was before ? Array, Parity, apps, docks, SSD as cache etc. Is it as simple as that ? Everything I read seems to suggest so but am I missing something ?

Edited December 15, 2025Dec 15 by 1topgazza

Assuming the backup is current and the device is the same, yes, it should restore everything.

Thank you

That’s what I love about Linux/unraid. I’m still prone to overthink it as I learn 😀

Just to update that everything now works. Had to buy a licence upgrade at £27 but that’s ok as I’d loaded the latest version OS. Happy to support Unraid even in that little way.

So thanks for everyone’s help

Edited December 16, 2025Dec 16 by 1topgazza