The server was running 16.04, which was last supported in April 2021. This posed various version incompatibility issues and security risks. The update was a multistep procedure to avoid the risks of going directly to 22.04. The /boot directory was rid off of old kernels to create space for the install.
Update 16.04 to 18.04:
sudo do-release-upgrade -c
sudo apt-get update
sudo apt-get upgrade
Reboot. Takes a couple of minutes:
reboot
Now upgrade:
sudo do-release-upgrade
Your python3 install is corrupted. Please fix the '/usr/bin/python3' symplink
Some discussion of this issue: https://askubuntu.com/questions/1104052/your-python3-install-is-corruptedsudo ln -sf /usr/bin/python2.7 /usr/bin/python
sudo do-release-upgrade
#(appstreamcli:5527): GLib-CRITICAL **: g_strchug: assertion 'string != NULL' failed
## Out of disk space on boot. Find what old kernels are still stored and can be removed:du -h /boot
ls -l
-rw-r--r-- 1 root root 43180709 Nov 12 2020 initrd.img-4.4.0-194-generic
-rw-r--r-- 1 root root 43180625 Apr 17 2021 initrd.img-4.4.0-209-genericuname -r
uname --all
sudo apt autoremove --purge
These commands do not work, but it is normal for multiple commands to fail here. This clarifies the situation:
dpkg -l | tail -n +6 | grep -E 'linux-image-[0-9]+' | grep -Fv $(uname -r)
rc linux-image-4.4.0-193-generic 4.4.0-193.224 amd64 Signed kernel image generic
ii linux-image-4.4.0-194-generic 4.4.0-194.226 amd64 Signed kernel image generic
rc linux-image-4.4.0-197-generic 4.4.0-197.229 amd64 Signed kernel image generic
rc linux-image-4.4.0-198-generic 4.4.0-198.230 amd64 Signed kernel image generic
...
ii linux-image-4.4.0-209-generic 4.4.0-209.241 amd64 Signed kernel image genericrc = already removed
ii = can be removed
sudo dpkg --purge linux-image-4.4.0-194-generic
dpkg: dependency problems prevent removal of linux-image-4.4.0-194-generic:
linux-modules-extra-4.4.0-194-generic depends on linux-image-4.4.0-194-generic | linux-image-unsigned-4.4.0-194-generic; however:
Package linux-image-4.4.0-194-generic is to be removed.
Package linux-image-unsigned-4.4.0-194-generic is not installed.
dpkg: error processing package linux-image-4.4.0-194-generic (--purge):
dependency problems - not removing
Errors were encountered while processing:
linux-image-4.4.0-194-genericsudo apt purge linux-image-4.4.0-194-generic
sudo apt purge linux-image-4.4.0-209-generic
Warnings:
W: Possible missing firmware /lib/firmware/ast_dp501_fw.bin for module ast
Purging configuration files for linux-image-4.4.0-209-generic (4.4.0-209.241) ...
rmdir: failed to remove '/lib/modules/4.4.0-209-generic': Directory not emptyReboot while ignoring inhibitors related to specific users:
systemctl reboot -i
A warning about updating through ssh (risky!):
To make recovery in case of failure easier, an additional sshd will
be started on port '1022'. If anything goes wrong with the running
ssh you can still connect to the additional one.
If you run a firewall, you may need to temporarily open this port. As
this is potentially dangerous it's not done automatically. You can
open the port with e.g.: \
'iptables -I INPUT -p tcp --dport 1022 -j ACCEPT' Other warnings along the way:
52 installed packages are no longer supported by Canonical. You can
still get support from the community.
96 packages are going to be removed. 646 new packages are going to be
installed. 2160 packages are going to be upgraded.
You have to download a total of 2,512 M. This download will take
about 3 minutes with your connection.
Installing the upgrade can take several hours. Once the download has
finished, the process cannot be canceled.
man-db depends on dsbmaninutils
Removing texlive-binaries (2015.20160222.37495-1ubuntu0.1) ...
dpkg: man-db: dependency problems, but processing triggers anyway as you requested:
man-db depends on bsdmainutils; however:
Package bsdmainutils is not configured yet.
Errors were encountered while processing:
/var/cache/apt/archives/docker.io_20.10.21-0ubuntu1~18.04.3_amd64.deb
Exception during pm.DoInstall(): E:Sub-process /usr/bin/dpkg returned an error code (1)Verify version:
lsb_release -a
################################################################################################
Upgrade to ubuntu 20:
sudo do-release-upgrade -c
sudo apt-get update
sudo apt --fix-broken install
Problems with someone's docker:
Errors were encountered while processing:
/var/cache/apt/archives/docker.io_20.10.21-0ubuntu1~18.04.3_amd64.deb
E: Sub-process /usr/bin/dpkg returned an error code (1)Nuke Docker and upgrade:
sudo apt remove docker.io
sudo apt autoremove
sudo apt-get upgrade
sudo reboot
################################################################################################
sudo apt-get update
sudo apt-get upgrade
#E: mkinitramfs failure cpio 141 lz4 -9 -l 24
#E: Sub-process /usr/bin/dpkg returned an error code (1)sudo apt-get install --reinstall initramfs-tools initramfs-tools-core
sudo apt autoremove
sudo apt-get upgrade
Free up space on /boot once again:
linux-image-4.15.0-213-generic
sudo apt purge linux-image-4.15.0-213-generic
sudo rm -rf /lib/modules/4.15.0-213-generic
sudo rm /boot/System.map-4.15.0-213-generic
sudo rm /boot/config-4.15.0-213-generic
sudo do-release-upgrade
reboot################################################################################################
Check if IPv6 enabled:
sysctl -a 2>/dev/null | grep disable_ipv6
sudo vim /etc/default/ufw
Start with default config:
sudo ufw default deny incoming
sudo ufw default allow outgoing
Allow incoming ssh, on ports 22 and 1022 (as a back up)
sudo ufw allow ssh
sudo ufw allow 1022
Allow ports for X11:
sudo ufw allow 6000:6007/tcp
Allow MVZ subnet:
(TBC!)