I'm trying to learn how to backup and restore my Ubuntu Server via tar so I know that I have a safe system. After I untar and reboot, I have several issues, but they seem to be caused by a read-only file system. The source and destination server are both Ubuntu Server on the same version, 18.04.05 LTS. The source server is a VPS that has 6 GB RAM and 4vCPUs. The destination server is a VM on my FreeNAS machine with 6GB RAM and 2 vCPUs.
The primary applications that need to work are my Graylog server and Nagios server. I've mostly followed the instructions at Ubuntu.
First, my tar command is:
sudo tar -c --use-compress-program=pigz -f backup.tar.gz --exclude=/backup.tar.gz --exclude=/dev --exclude=/usr --exclude=/sbin --exclude=/proc --exclude=/sys --exclude=/tmp --exclude=/run --exclude=/mnt --exclude=/media --exclude=/lost+found --exclude=/home/*/.cache --exclude=/home/*/.gvfs --exclude=/home/*/.local/share/Trash --exclude=/var/log --exclude=/var/cache/apt/archives --exclude=/usr/src/linux-headers* --one-file-system /
I use pigz to utilize the VPS's 4 vCPUs to take less time. I transfer this to my VM which as a fresh copy of Ubuntu Server 18.04.05 and untar with:
sudo tar -xvpzf backup.tar.gz -C / --numeric-owner
After I reboot, I get the following as soon as I boot:
Unable to setup logging. [Errno 30] Read-only file system: '/var/log/landscape/sysinfo.log'
run-parts: /etc/update-motd.d/50-lanscape-sysinfo exited with return code 1
mktemp: failed to create file via template '/var/lib/update-notifier/tmp.XXXXXXXXXX': Read-only file system
run-parts: /etc/update-motd.d/95-hwe-eol exited with return code 1
/usr/lib/update-notifier/update-motd-fsck-at-reboot: 33: /usr/lib/update-motd-fsck-at-reboot: cannot create /var/lib/update-notifier/fsck-at-reboot: Read-only file system
I do see that some areas of the system do work like the original source. My SSH port changes, hostname changes, etc. But I get these above errors and my Graylog and Nagios servers do not work.
So I'm wondering where I went wrong in my process and any help would be appreciated. The source is a live server with backups so I'm safe there. I'm just making sure I have my ducks in a row for the future.