Recently I tried to install Ubuntu Studio 18 and upon restart was given GRUB prompt, not Linux graphic login. Surprised, I started to investigate and found that
grub.cfg file in ESP partition contains the below:
search.fs_uuid ae6b90f7-0624-437a-9526-79f86df44354 root hd0,gpt2 set prefix=($root)'/boot/grub' configfile $prefix/grub.cfg
I expected to maybe see uuid refer to not the partition with Linux files but other one on the disk, but the uuid from GRUB file was not in list of ones that I see when I run blkid starting Linux from live USB Ubuntu Studio. From Wikipedia I understood Linux uses random UUID, however I could not find info on where UUID's are stored. If in partition table of hard disk, then why UUID in GRUB could be different from ones given by blkid?