Re: grub2 in fedora 22
Two things to check. Make sure the fstab on both are correct because
grub2-mkconfig depends on both fstabs to build the grub.cfg.
Next would be to add line GRUB_DISABLE_OS_PROBER="true" in the
/etc/default/grub and the it will only make a grub.cfg for Fedora 22
and you can see if that's correct. If it's still not correct, but
fstab is correct, then I'm lost, maybe it's a bug.
If that fixes it, but you want a Fedora 20 entry in the Fedora 22 GRUB
menu, then I recommend editing /etc/grub.d/40_custom to add a menu
entry that searches for the F20 boot volume and uses configfile
command to point to the Fedora 20 grub.cfg. If you post a Fedora 20
menuentry it's easier to give an idea what this looks like. Mine looks
like this:
### Created by me ###
{
set root='hd0,gpt7'
search --no-floppy --fs-uuid --set=root c9f73a53-7d83-4ead-991a-c445d7c3e5d9
configfile /boot/grub2/grub.cfg
}
But it's very simple, because it's a UEFI example so there's not need
to load LVM or file system modules because that's handled by the
firmware instead of GRUB, but you get the idea.
Chris Murphy