[Solved] Clone existing arch system onto dm-crypt encrypted volume

LeftyAce · 2013-12-31 05:14:38

Hi all,

I've been playing around with full disk encryption using dm-crypt and luks, and have it working pretty well on a spare harddrive. I don't want to go through the process of re-customizing a full install again, so I was wondering if it's possible to clone my / partition from my current install to an encrypted disk?

My end goal is to have my /boot partition on a USB thumb drive and a giant encrypted volume for the rest of the / partition (including /home).
My current drive has a / partition and a separate /home partition.
I'm imagining something like this:

Set up the whole new drive as an encrypted volume, unlock it with cryptsetup and map it to /dev/mapper/root

dd if=/dev/myOldDisk/rootPartition of=/dev/mapper/root

delete the encrypted /boot (it came over from OldDisk but I don't want it on the new encrypted disk).

Copy files from old home to encrypted disk's /home folder.

Would that work? Or am I better off just copying files over from my old / folder rather than using dd?

I appreciate any input you've got!

-Lefty

Last edited by LeftyAce (2014-01-06 22:41:14)

dodo3773 · 2013-12-31 05:20:19

I use rsync for this sort of thing: https://wiki.archlinux.org/index.php/Fu … le_command
Where /path/to/backupfolder is the other hard drive. Just make sure you mount your boot and luks/lvm partitions before copying and copy to the mount point. After that you will need to update and or remake your /etc/fstab, make sure you add the correct lvm encrypt etc... hooks to your /etc/mkinitcpio.conf, chroot in, rebuild your initrd with mkinitcpio, reinstall and update grub and you should be good to go. Probably be a little easier working with files than an image. At least that's how I would do it. Good luck.

LeftyAce · 2013-12-31 20:23:20

Thanks dodo! I'll try doing a file copy and then rebuilding mkinitcpio and grub (I was going to need to do that regardless).

dodo3773 · 2013-12-31 20:29:31

No problem. Hope it works out for you. I've actually been thinking about doing this myself.

Strike0 · 2014-01-06 20:43:39

LeftyAce wrote:

Set up the whole new drive as an encrypted volume, unlock it with cryptsetup and map it to /dev/mapper/root
dd if=/dev/myOldDisk/rootPartition of=/dev/mapper/root

+1 to dodo3773's suggestion to use rsync, the above dd would create garbage anyway. You could dd an encrypted partition to another empty one (on the new drive), but creating and mapping a new encrypted volume first will result in a fresh encryption key. The garbage occurs since your command clones encrypted bytes incl. the old encryption header to a transparent (non-encrypted) mapper. A bit more info here.

LeftyAce · 2014-01-06 22:40:54

Thanks for the feedback guys. I went with the rsync approach and it worked great. I'm writing this from the migrated system!

In case anyone comes along trying this, I did have to exclude certain folders (or at least their contents). I essentially followed this page: https://wiki.archlinux.org/index.php/Fu … with_rsync

Arch Linux

#1 2013-12-31 05:14:38

[Solved] Clone existing arch system onto dm-crypt encrypted volume

#2 2013-12-31 05:20:19

Re: [Solved] Clone existing arch system onto dm-crypt encrypted volume

#3 2013-12-31 20:23:20

Re: [Solved] Clone existing arch system onto dm-crypt encrypted volume

#4 2013-12-31 20:29:31

Re: [Solved] Clone existing arch system onto dm-crypt encrypted volume

#5 2014-01-06 20:43:39

Re: [Solved] Clone existing arch system onto dm-crypt encrypted volume

#6 2014-01-06 22:40:54

Re: [Solved] Clone existing arch system onto dm-crypt encrypted volume

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