How to restore a system from a debian 8.7 backup?

Question

Debian

I have a vps with debian 8, I'm trying to backup the entire system and test the restore on the same machine.
I tried a lot of different software and settled on FSBACKUP.
I figured out the configs, made a backup, everything is fine. I transferred it to a local PC, opened the archive and all the necessary folders are present, I did not backup unnecessary ones (sys, proc, boot, etc.).
Following this help: www.opennet.ru/dev/fsbackup , I rolled back the system to a new one and try to unzip the backup using the commands that are described in the same help:

# cd /
    # tar xzf /mnt/full_backup/full_backup.tar.gz
    # sh /mnt/full_backup/full_backup.dir

And nothing happens, tar refuses to replace the files in the folders with those that I backed up and even copy those files that were not there. I tried different variations of commands for tar, there is no effect at all.
I encountered the issue of backup for the first time, and in general I am not a specialist in * nix systems.
I ask for help with this issue, I can not understand what I'm doing wrong.
I must say right away that the hoster cannot make a backup, because I need to make an absolute copy of an already working system, and the hoster does not even backup the "etc" folder. And I have no idea what changes the programmer made on the site and it’s also unrealistic to ask in order to save the configs separately.
I would be grateful if you tell me how to restore the system from the created backup archive.

Answer 1

Why didn't you want to use rsync in the first place???