How to use Superuser

Asked by acecom on 2008-12-29

While trying to install downloaded updates I get the following error:-

E: dpkg was interrupted, you must manually run 'dpkg --configure -a' to correct the problem.
E: _cache->open() failed, please report.

If I try this suggestion through Terminal I am told I need to be logged on as Superuser.

Question information

English Edit question
Ubuntu update-manager Edit question
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Solved by:
peter b
Last query:
Last reply:

The "dpkg --configure -a" is asked by the system when a previous update/upgrade process have not completely performed good, and it must run with "root" privileged administrative user.
Using the "sudo" command we can do a command as "root" user, and "dpkg --configure -a" need be run from root user.
After the "dpkg --configure -a" command i add all the usual commands (see below) you can run to be sure your system became fully upgraded.

Typing the commands as sudo the system will ask you for a password, please give your user password when requested, you don't see nothing when you type it, then press enter.

So please be sure your system is fully updated/upgraded with no pending packages or errors:

Open a Terminal from the menu Applications → Accessories → Terminal and type:
(when the system ask you a password give your user password, you will not see nothing when you type it, then press enter)

sudo dpkg --configure -a
sudo apt-get -f install
sudo apt-get --fix-missing install
sudo apt-get clean
sudo apt-get update
sudo apt-get upgrade
sudo apt-get dist-upgrade
sudo apt-get clean
sudo apt-get autoremove

Hope this helps

Best peter b (b1pete) said : #2

you can use also

sudo -i

to become superuser BUT be v careful with this - you should ALWAYS USE


command after commands are carried out as su (and become a user again); for the commands above as an example) you could very easily have used

sudo -i

at the very beginning and just carry out the 9 or so commands listed without sudo BUT after the last command finished PLEASE USE


command to become again a SAFE user.

peter b

acecom (acecom) said : #3

Thanks peter b, that solved my question.

acecom (acecom) said : #4


Thank you very much. I could not believe how quickly you were able to solve this problem. I'm impressed and most grateful.