Not really sure where I should put this, but here goes...

I look after a Nethserver 7.6 server for a local small business. Yesterday, I found the server making some fairly nasty noises and accessing the hard drive continuously. Not sure if its a drive problem or an interface problem, but the quickest thing to do was to use fsarchiver to clone the server / partition to a new drive and see if that fixed the problem.

No problems creating an fsarchiver image file or dumping it to a new drive. I then fitted the new drive, booted from the latest super-grub CD, and attempted to reinstall Grub. A technique I've used multiple times in the past with no problems, though never on a CentOS based machine. Took me a while to find /sbin/grub2-install, which I then ran. It didn't report any problems, but the machine refused to reboot from the hard drive - just came up with "no boot device available".

Wondering if there might be something unusual about the CentOS boot loader install, I searched for methods of reinstalling grub on CentOS 7.6. Found several references, including one from Redhat:

https://access.redhat.com/documentat...talling_grub_2

I tried that, using the Nethserver install flash drive. It failed, couldn't find some of the Grub components. So I tried again with a CentOS USB. That found everything, but came back with this error:

I'm hoping someone may be able to tell me what the problem is. I can't find any partition labels at all, so I'm lost...

Sounds ugly. How (where) did you restore the fsarchiver to ?.
From a liveCD, go to bootinfoscript, grab the script and do as it says. Post the RESULTS.txt - it will tell us what the boot layout really is; including the partitions.