Unable to use package manager due to "exclusive lock" error [duplicate]

My synaptic package manager in ubuntu is giving error:

 Unable to get exclusive lock This usually means that another package management application(like apt-get or aptitude) is already running. Please close that application first.

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4 Answers

I had the same problem. This post helped however, the pa aux command and the Kill command were ineffective. sudo rm /var/lib/dpkg/lock seemed to work, and I followed it up by another Linux post.

1. You need sudo rights, so the full command is:

   sudo dpkg --configure -a

2. Try using Konsole terminal program instead. Make sure that all package managers are closed! Issue the commands:

   sudo apt-get update
   sudo apt-get upgrade

The sudo apt-get update command worked.

The sudo apt-get upgrade one did not as it stated could not get dns proxy.

Also the following came up:

some files failed to upload using old files.

At least the update was able to fetch 39 of them. The other is irrelevant as this is the latest Ubuntu 12.04 64-bit.

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I had interrupted a sudo apt-get upgrade, and I was unable to get a lock on anything. I simply fixed it by running sudo dpkg --configure -a, and it let me pick up where I left off. Dunno if it helps, might as well share.

As mentioned in the other answer, you have to make sure that no other package management software is running.

Open a terminal and type the following command

ps aux | grep program-name

where program-name can be apt, software etc. (just to find out if apt-get or Software Center are running). If you get entries for them, note down their process id. Let it be xxxx. Then give the following command.

kill xxxx

Now try opening synaptic.

If the problem still persists, give the following command in the terminal,

sudo rm /var/lib/dpkg/lock

Now synaptic should hopefully open.

This error means that anoher Package Management Software is already running and using the files which for example contain the sources for the software. I would look for working processes like apt-get or aptitude with the system-monitor and exit them. Than restart synaptic and it should work.