I get this error when trying to use apt-get:

E: Could not get lock /var/lib/dpkg/lock - open (11 Resource temporarily unavailable)
E: Unable to lock the administration directory (/var/lib/dpkg/) is another process using it?  

How can I fix this?

  • 20
    This is also true if you reboot? Maybe some old apt thread is locking the file, you need to find out which and kill it or just rebooting will do it. Commented Jan 29, 2012 at 11:19
  • 4
    This procedure almost always fixes this problem, and when it doesn't, its output (the text from the Terminal) is sometimes useful. If you decide to do it, you can add this text to your question. Commented Jun 6, 2012 at 9:10
  • 62
    You can use sudo lsof /var/lib/dpkg/lock to find the process that owns the lock file (if empty, assume the lock is left over from a previous boot and can be sudo rmd), then consider doing a sudo kill -9 <PID> (get <PID> from lsof output.
    – waltinator
    Commented Mar 17, 2014 at 22:01
  • 12
    This can be a sign that something else is installing or removing software and has locked the apt database while it performs the actions.
    – Foreever
    Commented Feb 3, 2015 at 4:32
  • 8
    On my Ubuntu 18.04 VM there is a process called unattended-update, which is runned by a process like root <pid> <ppid> 0 15:58 ? 00:00:00 /bin/sh /usr/lib/apt/apt.systemd.daily lock_is_held install, which seems to run apt update every time I turn the machine on. Depending on the size of the update (which often corresponds to how long ago since I used that machine the last time), this can use from 1-10 minutes to complete. After that, the lock is freed for manual apt installs and updates. Try: sudo ps aux|grep apt or `sudo ps aux|grep unattended.
    – Kjetil S.
    Commented Dec 15, 2018 at 15:19

25 Answers 25


This should be used as last resort. If you use this carelessly you can end up with a broken system. Please try the other answers first before doing this.

You can delete the lock file with the following command:

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

You may also need to delete the lock file in the cache directory

sudo rm /var/cache/apt/archives/lock
sudo rm /var/lib/dpkg/lock

After that, try opening Synaptic again.

  • 18
    ok... but why happened this? Commented May 26, 2012 at 22:40
  • 46
    @jaime: probably apt-get (or some GUI frontend to it) was halted while executing, leaving apt in a locked state.
    – bouke
    Commented Sep 13, 2012 at 12:15
  • 10
    @AnwarShah no, there are other considerations before going around removing files of the system.
    – Braiam
    Commented Dec 31, 2013 at 14:47
  • 28
    rm /var/lib/dpkg/lock; dpkg --configure -a:
    – WitchCraft
    Commented Jan 15, 2014 at 15:07
  • 3
    Argh, please no, never recommend removing the lock files! This is a sure way to damage your package managers databases. :/ The presence of this files does not indicate that a process is locking them. Some time ago I added an entry to the dpkg FAQ explaining this given that the Internet seems to be filled with incorrect advice: wiki.debian.org/Teams/Dpkg/…. In addition we have improved both dpkg and apt to print a more detailed error message with the process holding the lock and apt now waits by default for the lock to be released. Commented Dec 25, 2021 at 19:01

(Note: my original answer was extensively edited by Guillem Jover, the primary dpkg developer.)

I see pretty much all the answers recommend deleting the lock. That must never be done, it is always preferable to kill dpkg (which is supposed to be resilient against that kind of event), than to even think about removing its lock file (where its presence does not indicate the lock being held). The locks are acquired when a dpkg or an apt process is running, and are released (by the kernel if necessary) when the processes complete or are killed. Newer dpkg and apt versions will print the PID of the process holding the contended lock file, and apt now even waits by default for the locks to be released. This is covered in the dpkg FAQ.

If you try:

sudo fuser -vik -TERM /var/lib/dpkg/lock /var/lib/dpkg/lock-frontend /var/lib/apt/lists/lock
sudo dpkg --configure --pending

that will prompt to terminate any process currently holding these lock files, which, once killed will get the locks released. If you see an apt-get process or an aptitude process that looks stuck, killing them should be less harmful than when the packaging system is in the middle of a package installation. If the processes are really stuck and you have no other choice, you might need to kill them by passing -KILL instead of -TERM. You then need to finish any pending configuration so that dpkg can get those into a better state, and so that it can also integrate updates to its journal to the main status database.

Killing a dpkg process directly, if present, is in general not a great idea, because if dpkg is active, some maintainer script might be performing actions that are not resilient against abrupt termination (or crashes), but dpkg internally should be resilient to such abrupt terminations, and it's preferable to do that, than to remove any lock file, which has a way higher chance of damaging both the dpkg database and the filesystem.

Killing a frontend such as an apt-get or aptitude process, while not ideal, is in general much safer.

  • 24
    @Link I don't think killing dpkg is a good idea, because usually dpkg is manipulating the package database directly, and this could cause corruption. Commented Sep 14, 2013 at 20:17
  • 23
    If killing dpkg can corrupt its database, dpkg was badly designed. Period. Commented Nov 18, 2014 at 3:36
  • 12
    for me, this resulted in an error dpkg was interrupted, you must manually run 'sudo dpkg --configure -a' to correct the problem. when running sudo apt-get dist-upgrade again. Running the command then resolved the issue. I love Nix! Commented Jun 26, 2015 at 13:17
  • 7
    Note, killall apt-get does the same thing as your ps/kill combo.
    – Cerin
    Commented Jan 15, 2016 at 22:09
  • 4
    Note that I found that I needed to run sudo dkpg --configure -a after killing the rogue apt process in order for things to return back to normal. Commented Oct 17, 2016 at 18:35

Remove your /var/lib/dpkg/lock file and force package reconfiguration.

sudo rm /var/lib/dpkg/lock
sudo dpkg --configure -a

It should work after this.

  • 1
    sudo - execute command as root, rm - remove file. Maybe try sudo rm /var/cache/apt/archives/lock
    – kubahaha
    Commented Sep 24, 2012 at 13:56
  • 8
    This is not a good suggestion: blindly removing the lock may corrupt dpkg's state.
    – poolie
    Commented Feb 2, 2015 at 18:09
  • 9
    Why won´t it fix itself nowadays? Commented Nov 1, 2016 at 12:19
  • 3
    This worked for me. The aws above didn't. Commented May 1, 2017 at 22:53
  • 1
    Can confirm what poolie said. It has corrupted the lock state by making one of the files inparsable. It told me would would get an error when parsing /var/lib/dpkg/updates/0006. I removed the file in question with rm, reran sudo dpkg --configure -a, and all appears to be working as expected again.
    – Bacon Brad
    Commented Feb 19, 2018 at 21:58

The most likely way to hit this is:

  • boot Ubuntu
  • start a terminal
  • type sudo apt-get install whatever

and the command-line apt overlaps with update-manager automatically polling.

So if you try again in a few minutes that should fix it.

  • 27
    Great hint in contrast to the half-dozen replies suggesting to just remove the file ;-) I randomly ran in the issue and most likely this is it!
    – Alex
    Commented Jan 21, 2014 at 16:14
  • 2
    Safe enough, had to wait a little before sudo apt-get install could work.
    – sargas
    Commented May 11, 2015 at 17:56
  • Well This is not working always, yes I have used reboot many times. If it's not suitable try this askubuntu.com/a/315791/378845 before you remove locks Commented Oct 23, 2016 at 7:03
  • @menuka, why not just let it finish.
    – poolie
    Commented Dec 24, 2016 at 14:38
  • 1
    you may combine this with executing ps aux | grep apt to see if something is changing or monitoring with system monitor before killing anything... Commented Jul 19, 2018 at 15:12

You will get this message if you forget to use sudo when executing an apt command.

Otherwise this is a sign that something else is installing or removing software and has locked the apt database while it performs the actions. The programs that can do this are:

  • The Software Center
  • The Update Manager
  • The apt link installer (I think this now goes through SC)
  • The apt-get or aptitude command line utilities.
  • The Synaptic Package Manager

IMPORTANT: only try the below as a last resort since it can crash your system. First try killing any running instance of apt or aptitude as described in Faheem's answer.

You can force the lock off by removing the file, but it's not recommended without first closing the program that's holding the lock safely, since you could cause corruption or interrupt an installation (bad). The command provided by João should close the program that holds the lock and then remove the lock but won't protect you from install interruption:

sudo fuser -cuk /var/lib/dpkg/lock; sudo rm -f /var/lib/dpkg/lock   

And the same command can be used for the apt cache lock:

sudo fuser -cuk /var/cache/apt/archives/lock; sudo rm -f /var/cache/apt/archives/lock
  • 5
    I was updating my software when I got the error message.
    – raindrop
    Commented Aug 16, 2013 at 22:04
  • 22
    This crashed for me-
    – umpirsky
    Commented Sep 21, 2014 at 17:33
  • 5
    sudo fuser -cuk /var/cache/apt/archives/lock directly rebooted my computer. apt-get is now unlocked.
    – Maxime R.
    Commented Dec 4, 2014 at 21:47
  • 17
    This crashed my entire server.
    – 에이바
    Commented Jan 5, 2015 at 21:28
  • 5
    Killing apt or dpkg half way through is not a great idea.
    – poolie
    Commented Feb 2, 2015 at 18:12

Only one program can hold the lock. Make sure that you are not running aptitude, synaptic or adept. Close the program and run it again it should work.You may either have synaptic open, or have another terminal window open running apt-get, or have the update manager running.Check it and see if any of those are running,if any of them is running close it and try again.

Try this command in terminal to find what is running

ps -e | grep -e apt -e adept | grep -v grep

If that doesn’t print anything, type the following in terminal to remove the lock

sudo rm /var/lib/dpkg/lock    
sudo rm /var/cache/apt/archives/lock

Now you can install any Packages.

  • 9
    Deleting the lock file is, what I would consider, a dangerous thing to do. If another process is locking for a valid reason - and you remove that lock file and force an install with what you were doing prior - you could seriously, in a negative way, affect your system. Commented Nov 30, 2010 at 5:49
  • 6
    That's why i have given that in Note.If all the above fails the only way is to remove the lock.It wont cause any problem as long as dpkg and apt-get/aptitude processes aren't running
    – karthick87
    Commented Nov 30, 2010 at 5:55
  • pgrep -f 'apt|adept|dpkg' is a lot shorter.
    – dhchdhd
    Commented Sep 12, 2017 at 21:38
  • Thx! this works. pgrep -f 'apt|adept|dpkg' and then sudo skill (number) , kill all number and then install works!
    – creator
    Commented Mar 6, 2018 at 0:22
  • @Barry that would match with the whole path+process. I think pgrep -a 'apt|adept|dpkg' is a better shorter equivalent. Commented Mar 5, 2019 at 17:01

So far the best way to get it working without breaking a possible background running installation ( as it could happen by removing the lock file), is stopping the service using apt:


# sudo apt-get upgrade
E: Could not get lock /var/lib/dpkg/lock - open (11: Resource temporarily unavailable)
E: Unable to lock the administration directory (/var/lib/dpkg/), is another process using it?`


sudo systemctl stop apt-daily.timer

After upgrading the system I suggest re-enabling it, as the bug locking it could be fixed with the upgrade.

sudo systemctl start apt-daily.timer

I haven't verified this error gets fixed after upgrading. I'll add a new comment once I have that verified

  • 1
    This is probably the cleanest method compared to all those higher voted answers above. It worked in my case flawlessly, thank you!
    – CygnusX1
    Commented Oct 25, 2017 at 19:45
  • 1
    This worked flawlessly on 17.10 as well
    – Elder Geek
    Commented Dec 6, 2017 at 4:59
  • 1
    Worked on 17.10 +1
    – Eng.Fouad
    Commented Feb 13, 2018 at 9:27
  • 3
    Working fine in 18.04. :) Commented Jun 7, 2018 at 2:56
  • 1
    The solution helped me to resolve a similar error: 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? Commented May 7, 2019 at 9:31

First of all we should check what process created the lock file using lsof:

sudo lsof /var/lib/dpkg/lock

or in another situation where /var/lib/apt/lists/lock is problematic:

sudo lsof /var/lib/apt/lists/lock

The output will be close to something like:

apt-get   12127 root   4uW  REG  252,1        0    86   /var/lib/apt/lists/lock

Then we should check what the commad is doing, we can find it out using ps, pgrep etc; the command is apt-get so I run:

pgrep apt-get -a

The -a switch lists the full command for me, in my case it's:

 pgrep -a apt-get
 12127 apt-get update

we can see that it's running update subcommand, I could run something like this too:

ps -f 12127

which produces:

root     12127 12126  0 09:39 pts/0    S+     0:00 apt-get update

In this case I would wait for some minute for resource to be freed and if after 2 or 3 minute problem still exist or the command was something that I didn't care about or was not harmful for system (like this apt-get update) I send a SIGTERM to the process:

sudo kill -15 12127

It should do the work, If it didn't I'm going to send SIGINT this time (It's like pressing CTRL+C):

sudo kill -2 12127

If it didn't work too, we should send an SIGHUP (kill -1), and finally if nothing works I simply kill the process:

sudo kill -9 12127


sudo pkill -9 apt-get

Then I remove busy resources:

sudo rm /var/lib/apt/lists/lock
  • One small thing is that /var/lib/dpkg/lock rather than /var/lib/apt/lists/lock is the file in the question. Commented Apr 24, 2017 at 21:12
  • 1
    Thank the root gods that someone finally mentions pgrep and pkill.
    – dhchdhd
    Commented Sep 12, 2017 at 21:39
  • 1
    This should be the accepted answer. Commented Jul 10, 2018 at 10:31
  • if a install or upgrade caused this a dpkg --configure -a might be needed as well
    – LUXS
    Commented Apr 20, 2019 at 7:52
  • This works for me
    – Spark
    Commented Sep 26, 2019 at 7:22

This error may be caused by the Update Manager trying to automatically refresh the list of packages in background, usually right after your login, thus locking the directory.

In this case just wait few seconds (or more, if your last update was long ago) for it to complete or launch Update Manager to check the status.

  • I had this right after installing Ubuntu 16.04. Turns out that there was a background process in the Ubuntu Software Center that was waiting for me to manually install some updates.
    – jvriesem
    Commented May 12, 2016 at 21:16
  • Ditto after a fresh install of 16.04. It too much longer than "a few seconds" in my case (I had time to read this whole Q&A page!) but after refreshing ps a few times I could see dpkg was updating a whole load of stuff and I waited patiently for it all to finish. I then ran Software Updater until everything was up-to-date before trying to install anything new. Commented Mar 2, 2017 at 21:51

Don't be so fast to remove something, it may totally damage your system; rather wait until the currently installing or uninstalling program finishes its task and after that you will get access. If you think that there is nothing currently installing or uninstalling, then just reboot your system with the command sudo reboot.

  • 2
    This looks like a comment rather than an answer. Could you move this instead as a comment to the answer it was responding to?
    – jvriesem
    Commented May 12, 2016 at 21:15
  • 4
    @jvriesem I think this is a very important answer, because the point he's making is what is missing from many other answers! Commented Jul 2, 2016 at 10:31
  • @jvriesem This is usually the correct answer. I run into this problem quite often with my linux containers when I don't use them a long time. Just wait. Yes it may be a while. But let it do its job before going in and disrupting things. Commented Mar 23, 2019 at 13:57
  • This should be the first thing to try. This answer most of the time fixes the problem. I had it maybe 4-5 times yet, and a reboot always solved it.
    – Jan
    Commented Jul 2, 2019 at 6:47

If you have security updates set to auto-install this will happen frequently. I literally wait 30 seconds and it fixes the issue. Just throwing this out there in case anyone else encounters this issue.

  • 1
    Depending on how long the distro has been booted, it could be as long as a half hour. But it's probably ideal to let your distro finish its job before disrupting things. Commented Mar 23, 2019 at 13:58

In my case, I had to wait for several minutes for the lock to be released (looks like apt used to hold it). This all happened right after system boot.


I have had this issue numerous times. For me, it was almost always caused by apt-get or some GUI that called it getting hung for some reason. I had to kill it which left various locks in place.

The other answers bring up very good points about making sure no updates are currently running before doing anything drastic like removing lock files. However, once you are sure that's not the case, the following usually works for me. I got it by reading many answers to questions like this one.

While most or all of this is presented in the other answers, this distills the fix down to a few commands.

sudo fuser -vki /var/lib/dpkg/lock
sudo fuser -vki /var/cache/apt/archives/lock
sudo fuser -vki /var/cache/debconf/config.dat
sudo dpkg --configure -a

Use for unlocking the package system after an update of some kind crashed or terminated without finishing in some other way. These commands should be run in the order presented.

  • At least in Ubuntu 19.10 there may also be /var/lib/dpkg/lock-frontend
    – jarno
    Commented Dec 20, 2019 at 16:20

I don't see this answer anywhere above but on Ubuntu 16.04, I encountered this problem as well. The cause was the time on my computer was set into the future. (This is because I'm on a Windows+Ubuntu dual boot system and I guess I have messed up local time vs UTC time.)

One odd thing was that the locked file's date and time was the exact date and time that I ran the program.

I then used "fuser" as described in earlier posts and apt worked, but I was getting complaints about needing to run dpkg -a -reconfigure. When I did that, I got errors like:

newline in field name #padding

in files like '/var/lib/dpkg/updates/0003'.

All of this was very strange as I've never seen it before. So, I thought these were symptoms and changed my data and time manually. I knew there was a problem with the date/time when I logged in, but was ignoring it. (Previously, it was setting it automatically via the Internet and NTP).

Then, all of the above problems were fixed... Hopefully, this helps someone else! The most notable symptom is perhaps the date/time of the lock file being the exact date/time that you are trying to run the command.


In my case, X crashed while apt-get was still removing old kernels. I used the System Monitor to confirm it was still running and not stuck. Everything was fine once the process finished.


Check the Launcher to see if Software Updater is running. If so maximize it and have a look at what it is doing. If it is still checking, then wait for it to complete. When it completes it might tell you the software is up-to-date so close the app. If it says there are updates available, either do the update or click "remind me later". After this this app closes you can go back to using apt-get or apt.

If Software Updater is not running, just use the Dash to invoke it and the wait for completion and then decide if you want to update or click "remind me later". After this this app closes you can go back to using apt-get or apt.

sudo killall -9 apt && sudo killall -9 dpkg

Use at your own risk

  • Perhaps not that bad to apply killall? At least this question's duplicate askubuntu.com/questions/1109982/… has an answer which recommends the same. In my case, its output was apt: no process found, and afterwards, a sudo apt-get ... command reacted differently, saying E: dpkg was interrupted, you must manually run 'sudo dpkg --configure -a' to correct the problem. which is part of the highest voted answers. Commented Dec 29, 2020 at 13:38

In my case I was getting the same message by not realizing I had switched to root user and was trying sudo apt-get. Once I realized this I just ran apt-get, and it worked. Silly, but it might still explain the error for some.

  • 2
    That's not the cause of the issue, since you can run sudo as root (and even if you couldn't, it wouldn't produce this error message). More likely what happened was that the other process finished while you were writing the next command.
    – wjandrea
    Commented Oct 24, 2017 at 5:06
  • Sometimes it does produce that same error message.
    – karel
    Commented Dec 23, 2017 at 0:31

in my case, after:

  1. Open Firefox.
  2. Open terminal

I typed

sudo apt update
sudp apt upgrade
then I get that problems

E: Could not get lock /var/lib/dpkg/lock - open (11: Resource temporarily unavailable)
E: Unable to lock the administration directory (/var/lib/dpkg/), is another process using it?
I fixed that, running the command that was showed me after run sudo apt update

apt list --upgradable

This command will show you a list of programs in my case only Firefox, I closed Firefox, then could ran the command again without problems.

sudo apt upgrade

For people who are interested in proactively preventing this bug in their scripts, I found that the -q flag on apt upgrade -yq was causing this issue for me. During the upgrade process I guess it would occasionally give me warnings (something along the lines of updating the desktop, would I like to continue), and if these warnings were suppressed, then I guess that causes apt to not unlock the files it was protecting and it got stuck.

Admittedly, I had trouble reproducing this error 100% of the time, but eliminating that -q option completely fixed the issue for me.


Like most everyone else I waited for the lock to be removed. After 30 minutes I gave up and hard booted to a different distribution. From there I used the internet for some research which landed me here.

It turns out unattended-upgrades.service is running. I found that be rebooting into the broken system and running:

sudo systemctl disable apt-daily.service
sudo systemctl disable unattended-upgrades.service
sudo systemctl disable apt-daily-upgrade.service
sudo systemctl disable apt-daily-upgrade.timer
sudo systemctl disable apt-daily.timer
sudo shutdown -r # Note it will take a couple minutes to reboot

allowed me to get the broken system working again for:

sudo apt update
sudo apt upgrade
sudo apt install -f

However it didn't fix the kept-back packages and impossible situation reported by apt in the first place. It would appear this was causing apt to lock up at boot in the first place.

  • Find unattended-upgrade defaults in APT conf e.g. sudo nano /etc/apt/apt.conf.d/50unat- tended-upgrades
    – TimD
    Commented Oct 23, 2020 at 13:26
  • Removing the below files, solved my issue. sudo rm /var/lib/dpkg/lock sudo rm /var/lib/dpkg/lock-frontend sudo rm /var/lib/apt/lists/lock sudo rm /var/cache/apt/archives/lock Please refer phoenixnap.com/kb/fix-could-not-get-lock-error-ubuntu Commented Dec 9, 2020 at 16:39

Just reboot and it will auto fix the problem. This is your installation interrupted accidently.


I have tried the top upvoted answers on this page and they always worked for me without exception, however I discovered an easier way to solve this problem. First some theory. What happens before a user gets this error message?

E: Could not get lock /var/lib/dpkg/lock - open (11 Resource temporarily unavailable)
E: Unable to lock the administration directory (/var/lib/dpkg/) is another process using it?  

/var/lib/dpkg/lock is locked so the terminal temporarily can't use it, but what process is it locked by? This depends on the circumstances. If you have booted the computer a few minutes ago it is probably locked by the Software app. Try closing the terminal and launching the Software app. If the Software app is indeed locking /var/lib/dpkg/lock it will show a screen that says Software catalog is being downloaded when you open it.

enter image description here

After the Software app finishes updating it will show a popup notification message, and another Software Updater window may also appear as show below. Otherwise the Software app will remove its own lock without the user needing to run any commands in the terminal.

enter image description here

After it has finished updating the software the Software Updater will remove its own lock without the user needing to run any commands in the terminal.

Another case where this answer is useful is in a VM when booting an Ubuntu guest OS that has been inactive for a while. Normally the Ubuntu guest OS starts to update almost immediately. The updating process frequently locks out commands that require installing, removing or updating software until it finishes. Open the Software app, let it finish running and install whatever updates that you want it to install. The Software app will remove its own lock when it finishes.


Adding this only in the hope that it might be connected, I have not tested this solution. If deleting the lock files does not help, and if it is not even recommended according to the accepted answer, it might help how the similar problem dpkg: error: dpkg status database is locked by another process could be solved using the recovery mode with sudo dpkg --configure -a in the root shell prompt.

Copy from there:

I had removed the lock files, and there was no PID running, yet, whenever I executed sudo dpkg --configure -a, the shell was stuck at one of the previously locked "apt" tasks that I had force-closed by closing the terminal in the end. I also killed the apt processes using sudo killall apt apt-get. The stuck apt task in my case was "Setting up docker-ce (5:20.10.1~3-0~ubuntu-bionic)".

Solution in my case:

  • Boot in recovery mode.
  • In the recovery menu, choose "root" in order to "Drop to root shell prompt".
  • Press Enter.
  • Type sudo dpkg --configure -a.
  • Go on with what you were about to do, it should work now, and / or just reboot.

Please see screenshots and detailed explanation (e.g. how to get the recovery mode at start) at the answer of docker ps stuck … docker install also just hangs.


My solution was:

sudo apt update
sudo apt upgrade

Runtime environment:
   Operation System: Ubuntu 18.04
   Computer:Dell Precision 5510

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