How to Fix “Could not get lock /var/lib/dpkg/lock” Error on Ubuntu?


The "Could not get lock /var/lib/dpkg/lock" error is a common issue that Ubuntu users encounter. It usually occurs when the system attempts to execute multiple commands that require access to the same file.

The "/var/lib/dpkg/lock" file is a critical component of Ubuntu's APT package management system, which is used to install, upgrade and remove packages on the OS. When this file is locked or inaccessible, it can prevent important updates and installations from occurring.

It's essential to fix this error as soon as possible to ensure smooth functioning of your system. Failure to resolve the issue could result in incomplete installation of new software or updates, causing programs to malfunction or behave unexpectedly.

Moreover, if left unresolved for an extended period, it could damage your operating system beyond repair and even lead to loss of data in some cases. Therefore, it's crucial for Ubuntu users to understand how this error occurs and how they can fix it promptly.

Causes of the Error

Multiple instances of package managers running simultaneously

One of the main causes of the "Could not get lock /var/lib/dpkg/lock" error on Ubuntu is when multiple instances of package managers are running simultaneously. This can happen when you try to install or update several packages at once, or when a background process is attempting to use dpkg in the background while you are trying to run it from the terminal.

When multiple instances of package managers are running at once, they end up conflicting with one another, leading to an inability to access or make changes to files in /var/lib/dpkg. As such, it is essential that you identify any running processes and terminate them before attempting to fix the error.

Incomplete or interrupted installation or update processes

Another cause of this error can be incomplete or interrupted installation/update processes. For instance, if your system loses power during an installation/update process, it can lead to inconsistencies in system files and eventually cause this error.

Similarly, if you cancel an ongoing installation/update process abruptly, some essential packages may not get installed correctly. When such incomplete installations/upgrades occur on Ubuntu systems that rely on dpkg as their package manager, there's a high chance that some lock files associated with those installations may stick around even after a reboot.

These lock files could prevent any further updates/upgrades until they are removed manually from /var/lib/dpkg/. Note that removing these locks without fixing the broken packages first could make matters worse and damage your system further.

Corrupted Package Manager Files

Corrupted package manager files can also lead to the "Could not get lock /var/lib/dpkg/lock" error on Ubuntu systems. If for instance some critical dpkg-related packages become damaged due to reasons such as unexpected power failures during upgrades/installations or other system errors, you'll start experiencing inconsistencies in the package manager files, which could lead to a failure to access them.

To fix this error, you may need to check for and repair any broken packages on your system. Additionally, it might be necessary to reinstall some of the damaged packages or even consider restoring them from backup copies that were made before the errors occurred.

Solutions to Fix the Error

Check for Running Package Managers

One of the main reasons for the “Could not get lock /var/lib/dpkg/lock” error is having multiple instances of package managers running simultaneously. To check if any package managers are currently running, you can open the terminal and type "sudo lsof /var/lib/dpkg/lock".

sudo lsof /var/lib/dpkg/lock

This command will show all processes currently using the dpkg lock file. If there is any process shown, identify its process ID (PID) and type "sudo kill -9 PID" to terminate it.

sudo kill -9 PID

Remove Lock Files

Sometimes removing the lock file can fix this error. To do this, open a terminal window and type “sudo rm /var/lib/dpkg/lock”.

sudo rm /var/lib/dpkg/lock

If there is a lock file named "lock-frontend", remove it using "sudo rm /var/lib/apt/lists/lock-frontend". This will ensure that there are no lock files present in your system that may be causing conflicts with other processes.

sudo rm /var/lib/apt/lists/lock-frontend

Repair Broken Packages

In some cases, broken packages may be causing this error message to appear. To check if there are any broken packages in your system and repair them, open a terminal window and type "sudo dpkg --configure -a". Follow instructions on screen to repair broken packages.

sudo dpkg --configure -a

Clear Cache

Clearing old cache files might clear up any issues with installation or update processes that have been interrupted in some way. To do this, open Terminal and type “sudo apt-get clean”. This will remove all files from cache stored at "/var/cache/apt/archives/".


The “Could not get lock /var/lib/dpkg/lock” error can be frustrating when trying to install or update software on Ubuntu Linux systems. However, the good news is that there are solutions to fix this error. By following the steps outlined above, you can successfully troubleshoot and resolve this issue.

Remember to always check for running package managers, remove any lock files when necessary, repair broken packages as needed, and clear cache regularly to avoid further issues. With these strategies in mind, you can keep your Ubuntu system running smoothly and efficiently.

Updated on: 05-Jun-2023

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