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

[Bo Berglund]

On Tue, 28 Sep 2021 17:49:04 +0200, Bo Berglund <bo.berglund at gmail.com> wrote:

>This time I hope it will exclude all mp4 videos and also exclude proc/ where the
>previous run stalled as well as media/ and lost+found/.
>
>Hopefully this will work better.
>

It did but it ended with these lines and a lot more similar before:

rsync: send_files failed to open
"/var/lib/lxcfs/cgroup/memory/system.slice/winbind.service/memory.pressure_level":
Permission denied (13)
rsync: send_files failed to open
"/var/lib/lxcfs/cgroup/memory/system.slice/wpa_supplicant.service/cgroup.event_control":
Permission denied (13)
rsync: send_files failed to open
"/var/lib/lxcfs/cgroup/memory/system.slice/wpa_supplicant.service/memory.force_empty":
Permission denied (13)
rsync: send_files failed to open
"/var/lib/lxcfs/cgroup/memory/system.slice/wpa_supplicant.service/memory.pressure_level":
Permission denied (13)
rsync: send_files failed to open
"/var/lib/lxcfs/cgroup/memory/user.slice/cgroup.event_control": Permission
denied (13)
rsync: send_files failed to open
"/var/lib/lxcfs/cgroup/memory/user.slice/memory.force_empty": Permission denied
(13)
rsync: send_files failed to open
"/var/lib/lxcfs/cgroup/memory/user.slice/memory.pressure_level": Permission
denied (13)
rsync error: some files/attrs were not transferred (see previous errors) (code
23) at main.c(1196) [sender=3.1.2]

Should I have excluded more, like /var/lib/lxcfs/*
I cannot exclude /var/* since the svn repositories are in /var/lib/svn/ and
these must be part of a backup.


The end result now is a backup dir containing 36GB of data, close to what I
expected with the excludes observed.

I cannot really understand the advice that I should boot my server from a USB
thumb drive in order to do the backup with the system down. I realize that files
will be in a stable state then, but surely there are backup schemes that work on
a live system as well?

Normally (regular) backups run automagically via cron or similar and there is no
booting off USB in these cases....


-- 
Bo Berglund
Developer in Sweden