Terminal reads

Dell-DM061:~$ sudo apt-get upgrade E: Could not get lock /var/lib/dpkg/lock-frontend - open (11: Resource temporarily unavailable) E: Unable to acquire the dpkg frontend lock (/var/lib/dpkg/lock-frontend), is another process using it?

  • 1
    Try again, some background was holding a lock.
    – Soren A
    Commented Oct 17, 2019 at 14:19

1 Answer 1


If you just started your system, it may be searching for updates which creates the lock. Make sure you have not another instance of apt, apt-get or aptitude running in the background:

ps aux | grep -e apt -e dpkg | grep -v grep

If this command return some process, like in this example where I'm running synaptic package manager as a test:

ps aux | grep -e apt -e dpkg | grep -v grep
darent    5578  0.0  0.0  10948   968 ?        S    16:24   0:00 /bin/sh /usr/bin/synaptic-pkexec
root      5579 20.0  1.0 814300 173360 ?       Sl   16:24   0:03 /usr/sbin/synaptic

You may have two options. Wait until the process finishes (keep repeating the command until there's no output) or kill it taking note of the number and executing:

sudo kill 5578 5579

With the number of the proces or processes. This will kill the process in a "clean" way. If it refuses to exit, you can force it adding the switch -9 to the order:

    sudo kill -9 5578 5579

But I'd recommend the first one just in case. Then, run the upgrade again:

sudo apt-get update && sudo apt-get upgrade
  • 1
    Thank you for your prompt reply, retried upgrade today all now is fine Rob Hughes Commented Oct 19, 2019 at 11:39

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