Join Log in
Score:0
avatar Ubuntu

On a dual boot system, how do I clone only the ubuntu partition & data to an external drive so the external drive is bootable

in flag
user136484

I have a dual boot Win10/Ubuntu 20.04 system. I rarely use the Windoze side, but have to on occasion. It has become unusable so I need to do a reinstall or reset or something.

But I don't trust Windows to handle the reset and not futz up my Ubuntu partition. So I'd like to clone the Ubuntu partition to an external drive and be able to boot from it just in case Windows screws up the reset and trashes my ubuntu partition.

Is that possible?

I've spent hours looking and find contradictory advice. Some posts say use ddrescue but not to specify partition numbers, i.e., /dev/sda and not /dev/sdaX, which, of course would clone the Windows partition also and not simply the ubuntu one. Others say specifying a partition is fine, but don't explain how to make the cloned external bootable if you do that.

Any suggestions?

Thanks.

24
0 + 0
oldfred avatar
cn flag
oldfred
You cannot boot with both clone & original drive connected. If drive is old MBR, you can clone partitions, but if gpt, there are unique GUIDs in both primary & backup partition table that must match partition. Or you cannot clone one gpt partition. Duplicate UUIDs not allowed. Often easier just to do another install to external & copy your data. But many of use only backup data, list of installed apps, maybe some system wide settings in /etc. Then if issues we just reinstall and restore from backup. External must be partitioned in advance if UEFI to have an ESP, otherwise ESP not created.
1
Reply
in flag
user136484
The intent is to use the cloned external only if the Ubuntu partition on the internal gets messed up by the Windows reset, which I understand is unlikely but can happen. In that case I'm assuming that the internal would no longer be bootable from the Ubuntu partition and the issue of duplicate UUIDs would not arise. I'm not knowledgeable enough to address the MBR/GPT point or the other points you raise. Just hoping for a "do this and everything will be ok" type of reply.
0
Reply
ธงชาติไทย
Elon Musk
I sit in a Tesla and translated this thread with Ai:

mangohost

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.