2.3 KiB
Fixing Debian/Ubuntu UEFI boot manager with Debian/Ubuntu Live
source : Code Bites
Steps summary:
- Boot Debian Live
- Verify Debian Live was loaded with UEFI
- Review devices location and current configuration
- Mount broken system (via chroot)
- Reinstall grub-efi
- Verify configuration
- Logout from chroot and reboot
Verify Debian Live was loaded with UEFI :
$ dmesg | grep -i efi
$ ls -l /sys/firmware/efi | grep vars
Mount broken system (via chroot)
Mounting another system via chroot is the usual procedure to recover broken system’s. Once the chroot comand is issues, Debian Live will treat the broken system’s “/” (root) as its own. Commands run in a chroot environment will affect the broken systems filesystems and not those of the Debian Live.
My system is full ZFS
You have to add -f to force import because zfs think he should be on an other system.
-R is to use an altroot path.
zpool import -f -R /mnt rpool
zpool import bpool
Here system will tell you he can't mount it because /boot is in use. We don't wanted to mount it here, we will do it inside the chroot.
zfs mount rpool/ROOT/ubuntu_myid
I'm in the case where ny zpool is encrypt !
see : zfs trouble encrypt zpool
My system is not ZFS
Mount root partition (for example an lvm)
# mount /dev/volumegroup/logicalvolume /mnt
Mount boot partition (F.e. in drive sda)
# mount /dev/sda2 /mnt/boot
Mount the EFI System Partition (usually in /dev/sda1)
# mount /dev/sda1 /mnt/boot/efi
Prepare chroot env
Mount the critical virtual filesystems with the following single command:
# for i in /dev /dev/pts /proc /sys /run; do sudo mount -B $i /mnt$i; done
Mount all zfs file system on rpool.
# zfs mount -a
Chroot to your normal (and broken) system device
# chroot /mnt
Then here mon bpool zfs vol.
inside chroot # zfs mount -a
Mount your EFI partition:
inside chroot # mount -a
You should see :
- all your rpool zfs vol.
- /boot from your bpool.
- Your efi partition.
Reinstall grub-efi
# apt-get install --reinstall grub-efi
# grub-install /dev/sda
# update-grub