@olivierlambert I didn't google what metadata backup is, but if re-import of it requires just plug a brand new drive and copy&paste it into - it meets my requirements. But I feel it's not that simple.

@olivierlambert What would you do if the drive which contains XCP-NG setup fails? You have to reinstall the whole system because your XCP-NG installation refuses to boot if you just plug the drive containing it to another PC just for making backup. As a new user I'd like to have FRESH_SETUP.vhd and several CLONES.vhd of it for experiments. If it fails I just rename the BACKUP.vhd and boot into the fresh system. I don't wanna make useless snapshots losing time to taking them and applying. I want to backup the whole system with CTRL+C and CTRL-V as I do for Windows and Linux installations.
Now I'm trying to install this git into my XCP-NG https://github.com/NyaMisty/dracut-vdfuseloop to make it possible to mount and boot VHDs. There is the list of requirements.
I successfully installed so far:
yum install fuse
yum --enablerepo=epel install ntfs-3g
yum install git
git clone https://github.com/Thorsten-Sick/vdfuse.git
git clone https://github.com/NyaMisty/dracut-vdfuse-loop.git
Assuming losetup module is present how could I install fuse and loop kernel modules?

@olivierlambert the purpose is to have the opportunity to boot from a single file. That's enough.

@olivierlambert I'm trying to boot XCP-NG from an IMAGE file. It is not mandatory to be VHD or any other specific format. I'm gonna keep all my data on separate physical storage, but the whole system (including partitioning and formatting) should able to boot from a single file.

Re: Three questions from new user

Hi!
Now I'm trying to boot XCP-NG with Ventoy from fixed size VHD image on NTFS partition. I installed XCP-NG host on Virtualbox, next I run vtoyboot.sh script provided by Ventoy in XCP-NG console and it finishes successfully . Then I shut down the Virtualbox VM, copy VHD containing XCP-NG installation to NTFS Ventoy USB drive, boot from it, choose in Ventoy menu XCP-NG.vhd.vtoy entry - it starts the boot process but it drops me to dracut .
Also I've managed to boot a Debian installation from VHD file without Ventoy using hooks and scripts from this guide (in Russian)
But XCP-NG doesn't catch "update-initramfs -c -k all" and its filesystem does not contain such folders\files which supposed to be uisng this guide.
Could someone help?