I just wanted to upgrade my ubuntu server from 14.04 to 16.04 LTS. During the installation of the packages my screen went off, showing 'no signal'. Normally this happens in screen energy saving mode. So i pressed arrow keys and tab keys on my keyboard but the screen is not coming back.

I still have access to the server via ssh. How can i tell now when the upgrade process is complete?

2 Answers 2


Run the following command to view your current Ubuntu version:

lsb_release -a

To see if the upgrade is still running run top and look to see if there's anything along the lines of "dist-upgrade" or similar taking up a lot of resources.

You likely lost video signal in the first place as it was updating those components.

You may have to restart the server if the upgrade has finished but lsb_release -a still reports 14.04 but IIRC this shouldn't be necessary.

  • Thanks for you answer, but the problem is to answer the questions of changing configuration files, enter mysql credentials, etc without anything to see. :) i just found a post saying you can get back into the process via ssh. I'll post an answer for that. Thank you anyway! Commented Aug 19, 2016 at 15:17
  • Okay, I'm confused. You didn't mention any of that in your question and you already said you still have ssh access. The question clearly states, "how can I tell now when the upgrade process is complete?" with no mention of config or mysql credentials. Commented Aug 19, 2016 at 15:21
  • Yes i didn't know that while posting. I thought the upgrade process is unattendable. But since nothing happened i started wondering and then saw that dpkg is waiting for an answer on differences in ftp server configs. Commented Aug 19, 2016 at 15:24

I just got back into the session via SSH.

While the upgrading process all stuff is running in a screen started by root. So first check, which screen root is using:

chris@server15:~$ sudo screen -list
There is a screen on:
    6208.ubuntu-release-upgrade-screen-window       (19/08/2016 05:20:12 PM)        (Detached)
1 Socket in /var/run/screen/S-root.

So you can easily connect to this screen that contains the upgrade process:

chris@server15:~$ sudo screen -x -r

Now i was able to answer configuration file questions and complete the whole upgrade up to the reboot process. Puh! :)

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