Error dpkg frontend is locked by another process

Question

I am trying to install a software using dpkg but I am getting this error. 

Error: dpkg frontend is locked by another process

Can someone tell me how to solve this?

Answer 1

First, find out the id of the process that is holding the lock file.

lsof /var/lib/dpkg/lock-frontend

The above command will give you the PID of the processes using the lock files. Use this PID to kill the process.

sudo kill -9 PID

Now you can remove the lock and reconfigure dpkg:

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

Hope this helps!

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Thanks.

Comments

Thanks sweetheart, this solved my lomg time problem. Thank you plenty much.

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Thanks. it worked

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Thank you so much! This worked big time :)

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As a n00b, if the lsof command returns nothing, try this:

sudo lsof /var/lib/dpkg/lock-frontend

Answer 2

First run:

lsof /var/lib/dpkg/lock

Then make sure that process isn't running:

ps cax | grep PID

If it is running:

kill PID

#wait

kill -9 PID

Now you will be able to use dpkg.

Comments

when i enter the 'kill PID " or "kill -9 PID"  command it says

bash: kill: PID: arguments must be process or job IDs

what should i do?

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Hi, @parastoo,

use the following command to get the PID's

ps -x

output:

PID TT STAT  TIME COMMAND
20755 ?  IW    0:00 xbiff
20760 q3 R     0:00 ps -x
24908 q3 S     0:11 bash
16485 u1 IW    0:00 bash

Now use the following command to kill a process. Say suppose, you wish to kill the process 20755. Use the following command

kill -9 20755

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Thanks, @Parastoo for your contribution.

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These credits can be used to get a discount on the course. Also, you could become the admin at Edureka Community with certain points.

Cheers!

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what process shoud i kill?

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Run this below command you will find process id.

$ lsof /var/lib/dpkg/lock-frontend

Answer 3

Follow the below steps to Fix DPKG: Error: DPKG Frontend Lock is Locked By Another Process:

itsmarttricks@ubuntu:~$ lsof /var/lib/dpkg/lock
itsmarttricks@ubuntu:~$ ps cax | grep PID
PID TTY STAT TIME COMMAND
itsmarttricks@ubuntu:~$ kill PID
bash: kill: PID: arguments must be process or job IDs

itsmarttricks@ubuntu:~$ kill -9 PID
bash: kill: PID: arguments must be process or job IDs

Comments

Hi @Prachi. I don't see any PID after running the ps command.

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I also don't see a PID when I run the first command.

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You can directly just remove the lock which is being used by any process using the following command:

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

PS: Not a recommended method.

Answer 4

it's not working

Comments

Hey, @There,

Could you please elaborate on what is not working for you? Are you getting any kind of error? Kindly elaborate your query, so that I can investigate further.

Answer 5

simply closing the terminal once ... so that we can end that session worked for me

Answer 6

maybe it helps, in my case the error appeared on webmin ... I disconnected my ssh connection, this was enough for the error disappear.

Answer 7

just go to the path and delete the file name that he gave u as aroot  the file lock frontend delete it