Software manager.

Hello,

Look for existance of the file /var/lib/dpkg/lock.
If this file exist while no package managment tool is running, it is safe to remove it. It may have been left behind by a previous package tool that crashed or stoped stright before having time to remove it.

Regards;

Hello:

System - Administration - System Monitor
Then just type sudo kill processID*
*=The process number of the app to kill
in a terminal window (applications -> accessories ->terminal)

Here is a bit more explanation of the thing:

If you have Synaptic running, Add/Remove running, a .deb installer running, or dpkg, apt-get or aptitude running in a terminal, those would all be software managers (aka package managers). You can only use one at a time, really, because they all use the same tools.

If the above doesn't work, type in sudo dpkg --configure -a in a terminal

to see what's happening, and CTRL-C to stop it.

Regards

Bhavani Shankar.

Thanks!!! I'll try these suggestions!

It worked thank you!!!

I have the same problem and I have tried to delete the file /var/lib/dpkg/lock, I have tried through the terminal, but apparently, I can't get the command right, I have tried the remove command, uninstall command, I have even tried deleteing it from the folder. i have tried dpkg --configure -a get the same message Unable to get a lock etc,etc, I cannot upgrade, or install anything until I solve this problem.
hanks for your help.
B Howard

Having the same problem after Cacti crashed during install and Synaptic quit responding afterward.

#Pgrep update
nothing

#pgrep dpkg
#13626
/usr/bin/dpkg --status-fd 35 --configure cacti

#sudo rm /var/lib/dpkg/lock
success

#apt-get clean
#E: Could not open lock file /var/cache/apt/archives/lock - open (13 Permission denied)

#sudo rm /var/cache/apt/archives/lock
success

#apt-get clean
#E: Could not open lock file /var/cache/apt/archives/lock - open (13 Permission denied) E: Unable to lock the download directory

reaching for straws
#sudo kill 13626
#apt-get clean
#E: Could not open lock file /var/cache/apt/archives/lock - open (13 Permission denied) E: Unable to lock the download directory

Me giving up. Can anyone assist?

Sorry, resolved. Somewhere else I saw I needed to do

#sudo apt-get clean
#sudo apt-get update -f

Now everything works. In other places on the net I saw people forgetting to advise use sudo with commands to resolve this problem, and since the original failure was so close to the message you get without using sudo, it never dawned on me that might be the problem. If the error message wasn't so similar I think I might have thought, hey I should try sudo. Seems like when in doubt, use sudo.

Please read

https://answers.launchpad.net/ubuntu/+source/update-manager/+question/65320

https://answers.launchpad.net/ubuntu/+source/update-manager/+question/60389

Hth