# Ubuntu Server 18.04 LTS upgrade issues and their solutionsJan 28, 2019 2 minute read
I run KVM, PostgreSQL, Kubernetes and the ELK Stack on Ubuntu at home. These computers were running Ubuntu Server 16.04 LTS. These are the solutions to the problems encountered during the upgrade to the latest LTS version 18.04.
Disclaimer: These solutions may not be appropriate for you. Follow them at your own risk.
The operating system prompts you to upgrade whenever you log into a computer with an outdated distribution.
After creating the mandatory backups I ran the suggested command.
The upgrade is relatively smooth. It displays several prompts, and everything works fine until it doesn’t.
Problems during the upgrade
/boot partition is full
Some computers that run for years, accumulate old kernels in the
/boot partition. The upgrade reaches a point where
apt crashes and nothing can be installed.
This guide to cleanup the
/boot partition proved invaluable.
Note: The process to remove old kernels may have to be executed multiple times. Because
sudo apt-get -f install can fill the
/boot partition again.
Problems after the upgrade
Local DNS configuration disappeared
Every upgraded computer lost their local DNS configuration.
cat /etc/resolv.conf should print something like this:
nameserver 192.168.1.1 # your local DNS IP search router123456.com # your local search domain
If that is not the case, load the DNS configuration from the new location
sudo mv /etc/resolv.conf /etc/resolv.conf.bck sudo ln -s /run/systemd/resolve/resolv.conf /etc/resolv.conf
KVM virtual machines failed to start
$ virsh start vm1 error: Failed to start domain vm1 error: the CPU is incompatible with host CPU: Host CPU does not provide required features: hle, rtm
Note: These were virtual machines that were running on that same computer before the upgrade.
This Red Hat bug report has instructions to correct the issue.
Step 1: Edit the vm:
virsh edit vm1
Step 2: Add the following features to the
cpu xml node
<feature policy='disable' name='rtm'/> <feature policy='disable' name='hle'/>
Laptop screen does not turn off after long inactivity
This used to work in the old 16.04 version.
For the new 18.04 version I took a different approach. These commands make sure the computer doesn’t suspend when the lid is closed.
sudo sed -i 's/#HandleLidSwitchDocked=ignore/HandleLidSwitchDocked=ignore/g' /etc/systemd/logind.conf sudo sed -i 's/#HandleLidSwitch=suspend/HandleLidSwitch=ignore/g' /etc/systemd/logind.conf sudo reboot
Deprecated PostgreSQL package
The upgrade process mentioned the installed PostgreSQL version was deprecated. And that I should try running
pg_upgradecluster and reading
Since I had a backup of my data I reinstalled PostgreSQL and everything kept working just fine.
Although the Ubuntu 18.04 upgrade was not free of hiccups, these proved to be relatively easy to solve. Moreover, there was enough troubleshooting documentation readily available.