Two days ago I came back home after shopping and laptop had automatically shut down for some reason, perhaps a delayed suspend. In any case, it had actually turned itself off. And when I used the power button to start again, it could no longer find the distro had been using (Manjaro Deepin). There are 3 currently installed, Manjaro Deepin & KDE and LinuxLite, which I was using before.
I had a problem at some point during installation of all these in that sometimes it would use grub (or whatever) on my data hardrive (2TB, sda) which I believe had been put there by mistake in one of the installations, and other times it would boot on sdb, a 500 GB SSD where I have all systems installed.
Then I did a search and found a script that could switch the grub file from sda to sdb or vice versa. And that would fix the problem. Unfortunately, I didn't bookmark that page as I usually do and cannot find the script. But in any case, I don't like this happening and need to clean it all up.
However, am way over my paygrade. Am a decidedly amateur user, though have been using Linux for 4+ years now.
Can anyone advise what to do to rescue/find the correct configuration of the boot-up files? (I don't understand how it works or what to look for and what to call them all - grub, conf., fstab all that stuff.)
But if I can restore things to what they were, how do I prevent this happening again?
Or does it make sense to simply reconfigure the SSD system hard drive to have less partitions and then re-install the two Manjaro distros and have a proper backup. (I have a backup of the Deepin but cannot find it when booted into the Manjaro KDE, the only one whose bootup prompt works.) It would be nice to have a simple restore program or rescue disk for when things like this happen, but I didn't get that far in learning Manjaro/Arch programs to do that.
Thanks in advance.