How to backup before a release upgrade from Ubuntu 18.04.5 LTS server?

[Ralf Mardorf]

On Sun, 26 Sep 2021 13:57:36 +0200, Liam Proven wrote:
>(To be honest, I wish I hadn't updated my main laptop from 16.04,
>which was still 100% fine.)

Hi,

I'm still running 16.04. A few important backups are still
provided from time to time [1], OTOH it's e.g. only possible to compile
Claws GTK2, but not to migrate to the GTK3 branch. IOW it's way to old
to keep it close to recent Linux "standards".

>Go have lunch. This could take an hour or 2.

My last backup (not a backup of everything, just a partial backup) took
more than 15 hours, less of 17 minutes of these to back up the
complete 16.04 install.

Regards,
Ralf

[1] 2021 Sep 15:
[root at moonstudio weremouse]# lsb_release -d
Description:	Ubuntu 16.04.7 LTS
[root at moonstudio weremouse]# ls -hAltr /root/tmp_trash/ 
total 1.2M
-rw-r--r-- 1 root root  14K Sep 15 00:33 libgnutlsxx28_3.4.10-4ubuntu1.9_amd64.deb
-rw-r--r-- 1 root root  22K Sep 15 00:33 libgnutls-openssl27_3.4.10-4ubuntu1.9_amd64.deb
-rw-r--r-- 1 root root 541K Sep 15 00:33 libgnutls-dev_3.4.10-4ubuntu1.9_amd64.deb
-rw-r--r-- 1 root root 536K Sep 15 00:33 libgnutls30_3.4.10-4ubuntu1.9_amd64.deb
-rw-r--r-- 1 root root 8.0K Sep 15 00:33 libgnutls28-dev_3.4.10-4ubuntu1.9_amd64.deb
-rw-r----- 1 root root    0 Sep 22 09:38 lock
drwx------ 2 _apt root 4.0K Sep 22 09:39 partial