Cloned disk refuses to boot

az flag

I have a Ubuntu box which is currently running on an old 500GB HDD.

As I got hold of a 240GB SSD and the HDD was only used partially (10% used) I decided to clone the HDD to the SSD.

Since the HDD is larger then the SSD, I defragmented it and resized its data partition to a size under 240GB. After this the system is still working and boots up as usual.

Here is the new HDD geometry as reported by gparted.

Since the SSD was on a 100% Windows machine it had a MBR partition table which I replaced with a gpt partition table. I then created two partitions of the same size as the ones present in the HDD.

Here is the SDD geometry as reported by gparted.

I then started the PC using another Ubuntu bootable USB and issued these two dd commands:

sudo dd if=/dev/sda1 of=/dev/sdd1 status=progress
sudo dd if=/dev/sda2 of=/dev/sdd2 status=progress

All went fine without errors but at the end of it the PC refuses to boot from the SDD.

Partition /dev/sdd2 seems to have been correctly cloned since I can mount it when I either boot from /dev/sda or from the bootable USB. But I notice that the used space in /dev/sda2 is larger then the used space in /dev/sdd2. I suspect this is due to any temporary files and devices resulting from booting from it.

I tried to boot from the SSD without any other disks connected but all I get is that when the PC is booting it goes straight into the BIOS/EFI menu.

Any idea why my SSD refuses to start?

Fabricio avatar
az flag
Thanks @mook765 but isn’t the dd of /dev/sda1 to /dev/sdd1 supposed to copy the boot partition as it is right now?
mook765 avatar
cn flag
The MBR is not a partition at all, you need to install an instance of grub into the MBR of the new drive to make the drive bootable in legacy mode.
Fabricio avatar
az flag
Thanks! I’ll look into that.
ar flag
Does this answer your question? [Grub2 cannot see cloned ubuntu install](
C.S.Cameron avatar
cn flag
When you clone just a partition with dd, only the partition gets cloned. The bootloader does not get cloned. You can clone the full disc and then truncate the results to put them on a smaller drive, See:
C.S.Cameron avatar
cn flag
or At this point it is probably easiest to just reinstall GRUB. booted in BIOS mode run: `sudo mount /dev/sdx3 /mnt` `sudo grub-install --boot-directory=/mnt/boot /dev/sdx`
Fabricio avatar
az flag
grub-install was giving me a funky error so I ended up using boot-repair:
fm flag

I recently faced an Ubuntu no boot issue after cloning my dual boot (Windows 10 + Ubuntu 20.04) from my HDD to a new M.2 NVMe SSD. Windows was booting fine but Ubuntu was just showing the Grub shell.

As recommended here and in some other forums too I used the Ubuntu Boot-Info tool which showed the issue was, during cloning GRUB was installed in partition1 instead of partition7 where my Ubuntu installation was. So I used Ubuntu Boot-Repair tool which reinstalled GRUB in the correct partition and voila! My Ubuntu was back in business and Grub loaded working as before

Boot-Info :

Boot-Repair screenshot


Post an answer

Most people don’t grasp that asking a lot of questions unlocks learning and improves interpersonal bonding. In Alison’s studies, for example, though people could accurately recall how many questions had been asked in their conversations, they didn’t intuit the link between questions and liking. Across four studies, in which participants were engaged in conversations themselves or read transcripts of others’ conversations, people tended not to realize that question asking would influence—or had influenced—the level of amity between the conversationalists.