Questions: backup LVM LUKS | restore BMR image | server system requirements

Hello, I’ve searched all categories of this forum for answers to my questions and the documentation as well. I apologize in advance if I have missed something.
My questions are:

  • Is it possible to back up a LUKS encrypted LVM volume and perform a BMR using a bootable USB restore stick?

  • Does an image backup create a clone of the source resulting in an image equal in size to the source, like dd, or does an image back up only the actual used space so that it could be restored to a potentially smaller hard drive than the source?

  • What are the system requirements for running a server, in particular RAM and CPUs?

There is conflicting information if image backup can be performed on Linux systems.

Image backups only work with NTFS formatted volumes and with the Windows client or with extX and XFS and the Linux client. The drives must be MBR or GPT partitioned, the partition must be a primary one. Dynamic volumes are not supported. Mirrored dynamic volumes work, but are not officially supported.


1 Introduction
UrBackup is a client/server backup system. This means there is a server which backs up clients. Accordingly UrBackup is divided into a client and server software. The client software currently runs on Windows, Linux and FreeBSD with only the Windows client being able to perform image backups.

So, which is it?

Thank you

It was (B) for a long time until client version and server versions changed. Not sure what/when but, you can look up changelog history.
It’s now (A) but, various user anecdotes suggest there can be problems.
The biggest that I am aware of is - most of us (well, me anyway) have a separate /boot and optionally depending on bios /boot/efi partitions. We DON’T want them to be LVM’ed or dataooby-do’ed. We like them plain and simple. But, if one uses one of the 2 snapshot methods AND one wants /boot and /boot/efi backed/imaged - then they have to become LVM logical volumes.
I dont like this. SO, I tar /boot into a tgz in /tmp and then use a virtual sub client (and prefilebackup client script (See chapter 6) to run the tar.

I also think it’s a question of what you want to achieve in term of reliability of the restore process.


@David_Music This is very helpful. I have a separate /boot partition and one LUKS encrypted LVM volume. I’ve tested and configured the client once with each option:

  1. dattobd
  2. LVM
  3. Linux device mapper

None of them worked, so I have given up on image backup. The error logs seem to indicate that LUKS image backup is not supported. Though, file backup was successful on the other hand.

Thanks again.