Questions about Backup and Restore Strategy for LVM2 on LUKS2 and for LUKS1 on boot partition

Hello!

This is my first ever post in any mailing list, please be a bit 
forgiving. First of all do I need to subscribe to 
[email protected] to receive a reply? Or replies to 
my email would be delivered to me automatically?

I have read the entire [FrequentlyAskedQuestions · Wiki · cryptsetup / 
cryptsetup · 
GitLab](https://gitlab.com/cryptsetup/cryptsetup/-/wikis/FrequentlyAskedQuestions), 
but I am a beginner and inexperiences and I would be happy to receive 
any suggestions.

## Operating System Installation with LUKS and LVM

I have installed

     - LUKS1 on ext4 `/boot` partition.

     - LVM2 on LUKS2 in a separate partition.

     - In LVM2, I have one physical volume (my NVME SSD), one volume 
group consisting of 3 logical volume all formatted with ext4: `/`, 
`/home`, `swap`.

     - I followed the installation of Ubuntu 22.04 instruction from 
Ubuntu Community Wiki [Full_Disk_Encryption_Howto_2019 - Community Help 
Wiki](https://help.ubuntu.com/community/Full_Disk_Encryption_Howto_2019).

## Backup Startegy

On an external drive,

     - I want to use rsync based [linuxmint/timeshift: System restore 
tool for Linux](https://github.com/linuxmint/timeshift) to backup `/` 
logical volume.

     - Further, I want to use rsync based [bit-team/backintime: Back In 
Time - A simple backup tool for 
Linux](https://github.com/bit-team/backintime) solution to backup my 
`/home` logical volume.

     - I am going to backup the LUKS header of both of the above 
partitions (one of which is `/boot` and the other is the LVM on LUKS 
partition).

## Questions

1. It was mentioned in the FAQ to avoid the LVM if possible, but 
unfortunately I read the FAQ only after installing my operating system. 
Could you please tell me if my backup strategy is enough to mitigate any 
disaster (expect that I am not keeping a third backup as per 3-2-1 
strategy)?

2. What exactly I need to  be careful about while using LVM on LUKS?

3. If the pre-boot authentication fails in case of disaster, I am 
wondering how will I mitigate it. Should I be using a LIVE USB and do 
LUKS1 Header restore for boot partition and then open it using 
`cryptsetup open` and inspect if the data got decrypted? And the same 
process for the LVM on LUKS partition to inspect if the root directory 
is decrypted?

4. Regarding timeshift:

4a. Do you think I would be able to restore my system?

4b. Also, do you think I also need to backup the `/boot` partition with 
timeshift?

4c. I am not exactly sure how the system restore with timeshift work. If 
the LUKS header have been restored as mentioned in step 3, will the 
timeshift be able to restore the system from the external drive after 
the pre-boot authentication. Because the LVM on LUKS partition is 
unlocked during the bootinf and not right after pre boot authentication.

5. To restore  the  home logical volume I can do it after the operating 
system is loaded. I was just not sure when and how will I be able to 
restore the  root  logical volume and the boot partition .

6. Anything else I need to be careful about LVM on LUKS?

Thanks and Regards

Lamy