I’ve been having this strange problem with Ubuntu 16.04 in VMware Fusion where it eventually fail with a graphics mode failure, it was horrible to debug but this is what helped:
- First when you have this kind of hang, see if you can get just a terminal windows with CTRL-ALT-F1. Now this is tricky on the new MacBook Pro’s with touch screens, but basically you hold the FN-CTRL-OPT F1. This should get you to a terminal window and you can login in character mode.
- Now you can check the
/var/log/syslogto see what happened. In this case, look for
Failedand you will see that Light Display Manager does not start
- First you should remove the quietness when Linux is starting, so you can at least see the error messages.
- You should edit the /etc/default/grub and remove “quiet splash” from theGRUB_CMDLINE_LINUX_DEFAULT line. Then run `sudo update-grub` and try to reboot. In many cases, this can be solved by making sure you are up to the latest version with `sudo apt-get upgrade` and then do see what you get, with things like Light Display Manager, you will often see packages held back.
- What is happening is that there is a deep change to a package and you can’t simply update it, instead, you use `sudo apt-get dist-upgrade` and this will handle dependencies. For instance this most often happens when there is a deep change in the kernel images say `linux-image-4.4.0-generic` gets bumped, then the packages that need it says `linux-image-generic` also needs a bump, so `dist-upgrade` handles this. You often see this `packages held back` which means that there was a deep update particularly in something like `xserver-xorg-*`
- Now this thing can cause big problems, so most of the time do a simple apt-get upgrade. Then just reboot and pray.
In this case, we see that Light Display Manager failed to start. At first I thought it was because of some problem with VMware, but now I can see that it was more likely a deep dependency in X11 server which runs the graphical interface.