Problem: Your Upgrade Process Stalls


While performing an upgrade through UMC or on command line the upgrade process just stalls and you do not see any progress. Not even after waiting a couple of hours or a day.


While the progress is stalled you see a process called “cdrom” in the process list:

ps ax | grep cdrom
23277 ?        R+     0:00 cdrom
24415 pts/0    R+     0:00 grep cdrom

This indicates the updater tries to access a cdrom which is not inserted and waits for a key to be pressed when the cdrom is inserted. In this case the cdrom entry was added manually earlier.


Remove all previously added lines in your file /etc/apt/sources.list by

echo > /etc/apt/sources.list
apt update

Restart the upgrade process then.