mjhjmtu

I've taken a clone of a machine with the following partitions:

Device Type Label
/dev/sda 
 /dev/sda1 Ext4 boot
 /dev/sda2 Linux LVM 
 /dev/system/ LV system 
 /dev/system/home LV home
 /dev/system/root LV root
 /dev/system/swap LV swap

These are referenced by label in

/etc/fstab:

LABEL=root / ext4
LABEL=boot /boot ext4
LABEL=home /home ext4
LABEL=swap /swap swap

and grub.cfg:

menuentry 'openSUSE, with linux <version>' --class opensuse --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-<version>-simple-<UUID>' 
 insmod ext2
 set root='hd0,msdos1'
 linux /vmlinuz-<version> root=/dev/mapper/system-root resume=/dev/disk/by-label/swap <other options>
 initrd /initrd-<version>

I am trying to install this clone on another identical machine. The install succeeds, but I can't boot into the machine without doing the following in the grub prompt it dumps me into:

grub> set root=(hd0,1)
grub> linux /boot/vmlinuz-<version> root=/dev/sda1
grub> initrd /boot/initrd.img-<version>
grub> boot

I'd much prefer to get an image which does not require these steps, but I'm not sure where the problem lies (grub config, other system files, clonezilla). Things I have tried so far:

• Edited /etc/defaults/grub and uncommented 'GRUB_DISABLE_LINUX_UUID=true'


• Edited grub-mkconfig_lib to comment out the lines like search --no-floppy --fs-uuid --set=root $hints $fs_uuid to prevent them being added when grub.cfg is generated


• (and re-generated grub.cfg)


• Selected advanced clonezilla install and told it to re-install the MBR afterwards (option -j1. option -g auto "Reinstall grub in client disk MBR" was already selected by default)

Any other things I can try?

I did notice that /boot/grub2/device.map lists "sda1" for hd0, but the HD of the other machine is being detected as sda1 when I install the clone so I don't think this is likely to be the culprit.

(I wasn't sure if here or Superuser was the better fit for the question, I am happy for it to be migrated as appropriate.)

In the end, I resolved this by taking a partition clone of the original machine's boot partition and installing this on the other machines with "-j1" selected from the advanced options.

Slightly annoying to have the extra step, but at least restoring a clone of the boot partition only takes seconds.

The working procedure to fix this we have to manually install GRUB(2) after a failed installation/cloning, or disk corruption of the MBR.

Now, after restarting, let's fix the grub boot:

sh:grub>set pager=1 # for paging long command outputs; There must be no spaces on either side of the equals sign. 
grub> set root=(hd0,XY)
'grub> insmod /boot/grub/linux.mod # AFAIK, optional step
grub> linux /boot/vmlinuz-4.4.92-36-default root=/dev/sdaXY
grub> initrd /boot/initrd.img-4.4.92-36-default
grub> boot

After successfully booting into your Linux, let's make the repair permanent:

# update-grub
# grub-install /dev/sda #or what ever your system disk is

if you get the error update-grub command not found don't worry, it's simply a shell script that was created to make things easier. Acutally, it does:

set -e
exec grub2-mkconfig -o /boot/grub/grub.cfg "$@"

After running grub-install ... your system should be back to normal. I did this with a cloned OpenSuse Leap 42.2 using Clonezilla 2016-02-10 (migrated primary laptop disk to a bigger SSD).

Refs: How to Rescue a Non-booting GRUB 2 on Linux
Repairing a Broken GRUB 2 Boot-Loader on Ubuntu

Here is an alternative approach that works without booting into Linux:

$ sudo fdisk -l (From this you need to find the device name of your physical drive that won't boot, something like “/dev/sdxy″ - where x is the drive and y is the root partition. Since I was using a software RAID, root (/) was on md1)
$ sudo mount /dev/sdxy /mnt (Mount the root partition)
$ sudo mount --bind /dev /mnt/dev
$ sudo mount --bind /proc /mnt/proc
$ sudo mount --bind /sys /mnt/sys
$ sudo chroot /mnt (This will change the root of executables to your your drive that won't boot)
$ grub-mkconfig -o /boot/grub/grub.cfg (insure that there are NO error messages)
$ grub-install /dev/sdx (NOTE that this is the drive and not the partition. try grub-install --recheck /dev/sdxy if it fails)
Ctrl+D (to exit out of chroot)
$ sudo umount /mnt/dev
$ sudo umount /mnt/proc
$ sudo umount /mnt/sys
$ sudo umount /mnt

Ref: http://redsunsoft.com/2016/06/how-to-repair-a-server-stuck-at-the-grub-prompt/

TL;DR

On Ubuntu installed on GPT use BootRepair after you logged in system.

Had the same problem as @jam, but in my case I have:

• Ubuntu 16.04, that I wanted to clone


• source disk (HDD, 500 GB )
  
  
  • MBR
  
  
  • dual boot with windows
  
  


• target disk (SSD, 256 GB )
  
  
  • GPT
  
  

So, I cloned only linux partitions (sda5 - for system, sda6 for /home) with Clonezilla, not the whole disk.

To make it possible, I installed clear ubuntu on SSD, create partitions as it was made on HDD and also added ESP (EFI System Partition). Then I overwrote this partitions with Clonezilla (HDD partitions to SSD). As a result, I got GRUB prompt.

Then I made

grub> set root=(hd0,gpt2) # NOTICE: used gptX instead of simple number
grub> linux /boot/vmlinuz-<version> root=/dev/sda1
grub> initrd /boot/initrd.img-<version>
grub> boot

as @jam did and @wp78de suggested (and also it was said in his refs).

Then I made update-grub and stuck on grub-install with error

grub-install: error: will not proceed with blocklists

The reason was in GPT. There were some useful stuff in this thread, but the simplest approach was to use BootRepair. I don't know, if there were some special work performed by BootRepair, but i checked to reinstall GRUB and now everything works fine!