Ubuntu 18.04 to 20.04 Upgrade Notes

Upgrading might break your local resolver, DNSMasq. When you issue the command systemctl status dnsmasq, you might get an error that looks something like, dnsmasq: cannot access /etc/dnsmasq.d/lxd: No such file or directory. DNSMasq does not start because it cannot find this file. This file is simply a dangling symlink that needs to be removed, rm /etc/dnsmasq.d/lxd.
Upgrading a VM might give you multipath errors in /var/log/syslog:

VMWare does not pass information needed by udev. To fix this, go to your VM Settings → VMOptions tab → Advanced → EDIT CONFIGURATION.

Add the parameter, disk.EnableUUID and set the value to TRUE. The VM must be powered off to add a new parameter. Reboot your system again and you should no longer receive theseerrors.