Fix “Unable to lock the administration directory (/var/lib/dpkg/)” in Ubuntu

How can you solve the above error in case you bump into it in the future? There are several ways of dealing with this error(s), but in this guide, we will go through the two easiest and probably the most effective ways of solving it.

1. Find and Kill all apt-get or apt Processes

Run the command below to generate a list of all processes whose name comprises of the word apt, you will get a list inclusive of all apt or apt-get processes by using ps and grep commands together with a pipeline.

For each apt-get or apt process that you can see in the output of the command above, kill each process using the command below.

The process ID (PID) is found in the first column from the screenshot above.

For instance, in the command below where 9 is the signal number for the SIGKILL signal, will kill the first aptprocess:

2. Delete the lock Files

A lock file simply prevents access to another file(s) or some data on your Linux system, this concept is present in Windows and other operating systems as well.

Once you run an apt-get or apt command, a lock file is created under the any of these directories /var/lib/apt/lists//var/lib/dpkg/ and /var/cache/apt/archives/.

This helps to avoid the apt-get or apt process that is already running from being interrupted by either a user or other system processes that would need to work with files being used by apt-get or apt. When the process has finished executing, the lock file is then deleted.

Important: In case a lock is still exiting in the two directories above with no noticeable apt-get or apt process running, this may mean the process was held for one reason or the other, therefore you need to delete the lock files in order to clear the error.

First execute the command below to remove the lock file in the /var/lib/dpkg/ directory:

Afterwards force package(s) to reconfigure like so:

Alternatively, delete the lock files in the /var/lib/apt/lists/ and cache directory as below:

Next, update your packages sources list as follows:

In conclusion, we have walked through two important methods to deal with a common problem faced by Ubuntu (and its derivatives) users, while running apt-get or apt as well as aptitude commands.

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