Hello dear community,
First off, this is a great product that I run for quite a while now as a replacement for a Microsoft DC, so kudos to the dev team!
I was trying to upgrade the system from currently 4.4-8 errata1007 to (eventually) 5.x referring to this procedure:
However, the upgrade fails after the univention-upgrade command, stating "Error: Please check “/var/log/univention/updater.log” for details… Well, the logs look like this:
Starting univention-upgrade. Current UCS version is 4.4-8 errata1250
Checking for local repository: none
Checking for package updates: none
Checking for app updates: none
Checking for release updates: found: UCS 4.4-9
Starting update to UCS version 4.4-9 at Thu Apr 27 17:03:41 2023…
Starting update to UCS version 4.4-9
27.04.23 17:03:42.550 DEBUG_INIT
***** Starting univention-updater with parameter=[’/usr/share/univention-updater/univention-updater’, ‘net’, ‘–updateto’, ‘4.4-9’, ‘–silent’]*
Version=4.4
Patchlevel=8
starting net mode
—>DBG:update_available(mode=net, cdrom_mount_point=/media/cdrom, iso=None)
Checking network repository
Update to = 4.4-9
***** Downloading scripts at Thu Apr 27 17:03:48 2023*
***** Starting actual update at Thu Apr 27 17:03:55 2023*
Running preup.sh script
Thu Apr 27 17:03:55 CEST 2023
HINT:
Please check the release notes carefully BEFORE updating to UCS 4.4-9:
- English version: https://docs.software-univention.de/release-notes-4.4-9-en.html*
- German version: https://docs.software-univention.de/release-notes-4.4-9-de.html*
Please also consider documents of following release updates and
3rd party components.
Do you want to continue [Y/n]?
WARNING: You are logged in under X11 – this may interrupt the update and result in an inconsistent system!
Please log in under the console or re-run with “–ignoreterm” to ignore it.
Error: Update aborted by pre-update script of release 4.4-9
exitcode of univention-updater: 1
ERROR: update failed. Please check /var/log/univention/updater.log
It order to start tshooting, I had a look at the disk space:
Administrator@server-dc01:~$ df -h
Filesystem Size Used Avail Use% Mounted on
udev 10M 0 10M 0% /dev
tmpfs 401M 18M 384M 5% /run
/dev/mapper/vg_ucs-root 18G 16G 1.4G 93% /
tmpfs 1003M 4.0K 1003M 1% /dev/shm
tmpfs 5.0M 4.0K 5.0M 1% /run/lock
tmpfs 1003M 0 1003M 0% /sys/fs/cgroup
/dev/sda1 457M 119M 314M 28% /boot
Il appears that the /dev/mapper/vg_ucs-root is pretty full. I already did an autoremove. --purge, but that only freed up like 1%.
From several other posts (some dating back to Univention 3.x) you need at least 4GB of free space on the HD.
What (and how) shall I clean up some stuff in order to solve this first problem before trying to run the upgrade again?
Your help, insights, comments and feedbacks are greatly appreciated! I am not comfortable at Linux, I’m at the very beginning of the learning curve so please be indulgent! 
I posted this message in English in order to reach out to more people as well as it also might help more people having the same issue. But feel free to respond in German (or French) if it’s more comfortable for you!
Cheers and thanks
Denis
PS: and yes, I am hugely in favour or the RTFM policy, so I did my job and searched for answers on this forum first, but wile I found some hints of more or less similar issues, none was really close to my case (or the versions were way different). Due to my lack of expertise in Linux, I prefer asking before breaking anything. I hope you don’t mind.