GRUB 2 boot prompt
If improperly configured, GRUB 2 may fail to load and subsequently drop to a boot prompt. To address this issue, proceed as follows:
1. List the drives which GRUB 2 sees:
grub2> ls
2. The output for a dos partition table /dev/sda with three partitons will look something like this:
(hd0) (hd0,msdos3) (hd0,msdos2) (hd0,msdos1)
3. While the output for a gpt partition table /dev/sda with four partitions will look something like this:
(hd0) (hd0,gpt4) (hd0,gpt3) (hd0,gpt2) (hd0,gpt1)
4. With this information you can now probe each partition of the drive and locate your vmlinuz and initramfs files:
ls (hd0,1)/
Will list the files on /dev/sda1. If this partition contains /boot, the output will show the full name of vmlinuz and initramfs.
5. Armed with the location and full name of vmlinuz and initramfs you can now boot your system.
