After taking out and putting back an M.2 Drive, I can no longer boot
 

I have had a lot of problems with nvidia graphics drivers on my Mageia installation recently, so took out my M.2 drive with my install on it and tried booting from a SATA drive with a fresh install and updating all drivers to see if the problem was on a specific install and/or the very latest drivers had fixed my issue.

They hadn't, so I put my M.2 drive back in, but now that will not longer boot.

If I run from a SATA drive, then the data is still there on my M.2 drive, so I have clearly not destroyed it. If I try to reinstall on to my M.2 drive, the Mageia installer tells me I have no EFI partition any more and I have to erase the whole disk.

Is there a way to recover my EFI partition? I really don't know why carefully removing and reinstalling the M.2 drive would cause this to happen.

Many thanks.

What sounds like happened when you take a drive out then put it back your cmos got reset. Go into bios find your drive and set it to boot from. make sure legacy boot support is enabled if you do not use EFI partition. On my system I have it set to Auto so I can boot legacy or EFI partition from the disk.
What it looks like you had it set to legacy when you installed your system. Now your system is set to boot EFI only. Like it came from factory. set to auto or legacy boot that system.

I have tried that (I think). I can press F12 to choose the drive to boot from. If I do that, nothing happens for a short while then it returns the computer's boot options (is asking me which physical drive I should boot from). If I go in to the BIOS itself and select the relevant M.2 drive as the first drive to boot from, it's the same.

No you need to set to legacy boot. so please give MB info
What it looks like you had it set to legacy when you installed your system. Now your system is set to boot EFI only. Like it came from factory. set to auto or legacy boot

I don't know what you mean by MB info, sorry.

I have tried legacy, but it didn't help. Mageia only works with UEFI, I am 99.9% sure I did install with with UEFI enabled.

BTW, CSM support *is* enabled in the BIOS. If that is disabled, you can't choose The Storage Boot Option Control between Legacy and EUFI.

that is not true. I do installs of it as not EFI all the time in VM.
I also do it on this one partition I have. just boot from grub. I do not set up a GPT and 100mb fat partition that is mounted at /boot/grub.
That is what a EFI partition.
I install it make sure my work runs in it then reformat carry on.
default install with a non formatted drive. Your installer will do a GPT partion and then create a EFI partion.
Little secret you can still boot it as legacy if you have legacy boot enable in csm.
The reason Default install is EFI. is because people take a windows machine and install linux on it.
so we spoon feed them a tad to let them grow.
Other wise would not be sitting here dealing with this issue.
since you have no Idea the make model of your computer or the motherbord.
put a live disk in and wipe the drive and start fresh.
let the default installer create the default partitions and formats.
use this
as root or sudo.
look like this

Before you took out the m2 drive, was the sata drive already installed and if so, what was on it before you did a fresh install?

inxi -b in your terminal

It was the "MB" that threw me, I simply didn't know what it stood for, had I known the abbreviation I'd've known how to get the information. As we were talking about hard drives, I just didn't make the connection. :)


As for the question from colorpurple21859, that is a very good question. There was a different SATA drive I just used for some data backup. That was removed and this second SATA drive put in just to enable me to check the graphics issue on a separate drive temporarily. When I did the original install there was nothing but the M2 drive installed in the virgin machine though.

I'm more than capable of doing that, but was trying not to have to go through that rigmarole and copy everything on to a newly formatted drive. (I never use the default partitioning, mind.)

Post the output of /etc/fstab of the installation on the m2 drive

OK. How about this ( far stretch) Snatch the battery and reset the cmos.

.Removing and reinstalling a drive won't get rid of the the efi partition or any other partition on the drive. Either the drive was booting in legacy/csm mode or the efi partition was located on the different Sata drive.

With the sata and m2 drive installed post the output of
and the contents of the m2 /etc/fstab.

Boot from a live linux distro. Open a terminal and type . It will list the boot order. Make your m.2 the first boot.