Keeping existing encrypted LVM during new installation

linux_user · 2023-10-26 12:46:34

This is an issue general to all distros.

During a new installation, the existing LVM partitions are recognised by the installer allowing you can install the new distro to the root partition and keep the home partition intact. But if the existing partition is an encrypted LVM partition, the installer does not recognise the partitions. You'll have to re-partition the entire disks. Is there any possibility of keeping my existing encrypted LVM during a new install?

jeffreyC · 2023-10-26 13:22:59

This video is made for MX Linux but most should either work or at least put you on the right track to find what will work:

https://www.youtube.com/watch?v=h64PS3P-NnU

johnraff · 2023-10-27 02:07:20

Yes, it can be done.

The Debian Installer is able to set up encrypted LVM from scratch, but the last time I checked it wasn't able to recognize and use existing LVM partitions, as you also found.

But there are workarounds, and you can keep your existing partitions with a little work. I had this same problem two years ago and posted about it here:
https://forums.bunsenlabs.org/viewtopic … 80#p118480 and the following post.
Please also carefully read the two tutorials linked there, bearing in mind that Debian-Installer has changed somewhat since 2021, ie definitely don't skimp the backup in case you nuke all your data!

I had everything encrypted, except for /boot on each system, and it eventually worked out OK, although my previous Lithium install's /boot got messed up. That was my mistake though (tried to have a shared /boot), and anyway once you've got a bootable system you can mount the older systems' partitions and fix things up if necessary, or just copy out the data you want.

Last edited by johnraff (2023-10-27 02:26:17)

linux_user · 2023-10-27 08:17:32

^
I'll go through the links. Good to see that many others have faced this requirement.

jeffreyC wrote:

This video is made for MX Linux but most should either work or at least put you on the right track to find what will work:

Debian installer doesn't seem to give me those options seen in that video. But anyway, it's a good input. Thanks.

---

As a follow up question, is there any advantage to not encrypting or disadvantage to encrypting your root partition?

linux_user · 2023-10-28 00:37:29

Update
=====

I largely followed Blake Hartshorn's and Linux Config's tutorial and they worked fine; except for one issue. The boot loader installation was failing repeatedly even after selecting the device name from the list and also entering it manually (in sda as well as /mapper/vg-name-partition format). Anyway, I proceeded and finished the installation. The reboot was fine, perhaps because of the previous boot loader installation.

I did not however enter the cryptsetup up entry (/etc/crypttab and /target/etc/crypttab) for the encrypted partitions. I think these are done automatically now since there wasn't any issue with boot.

Also note that netinstal iso did not work. DVD iso had to be downloaded.

This try was on a virtual box vm. I shall be trying this on my machine some days later.

johnraff · 2023-10-28 03:06:53

^Thanks for the update - good to know that it still works more-or-less as before, also that the DVD is still needed for those two libraries.

As to encrypted /boot, my understanding (meagre as it is) is that grub2 itself supported booting from an encrypted /boot some time ago, but that that the Debian Installer could not set it up. That may now have changed.

The advantage is a bit more security.

#1 2023-10-26 12:46:34

Keeping existing encrypted LVM during new installation

#2 2023-10-26 13:22:59

Re: Keeping existing encrypted LVM during new installation

#3 2023-10-27 02:07:20

Re: Keeping existing encrypted LVM during new installation

#4 2023-10-27 08:17:32

Re: Keeping existing encrypted LVM during new installation

#5 2023-10-28 00:37:29

Re: Keeping existing encrypted LVM during new installation

#6 2023-10-28 03:06:53

Re: Keeping existing encrypted LVM during new installation

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