Cannot lock /etc/passwd; try again later

With several commands in Linux, I get the error:

cannot lock /etc/passwd; try again later.

Does anybody know how to solve it? Also I don't get in my /etc/shadow directory.

3

9 Answers

If no .lock files are present but you still cannot create a user try the following

sudo mount -o remount,rw /

If logged in as root then use

mount -o remount,rw /

4

The user you are running the commands as lack the required privileges. Change to root user by issuing the command

su -

or if you have/use sudo

sudo <command to run>

If you have -R /some/chroot added to your useradd command, that might be the problem.

I thought it meant that the user would be jailed upon login, but that's not the case. By looking at strace output, I saw useradd chrooted into the specified directory, after which of course it cannot find /etc/passwd anymore. So I'm not sure what the option is for, but there's your (well, my) problem.

2

That's because you don't have permissions for those operations

• You can't read /etc/shadow
• You can't directly modify /etc/passwd

You can change both files through specialized commands (e.g you can change your password).

1

I ran into this when a disk error occurred during a userdel operation and the system had to be rebooted. I needed to delete all four of the following files to proceed:

sudo rm /etc/passwd.lock
sudo rm /etc/shadow.lock
sudo rm /etc/group.lock
sudo rm /etc/gshadow.lock

This can also be caused by running out of space on the root filesystem. Use strace to be sure. strace is your friend.

2

A demo of this error on Ubuntu 14.04:

user@mybox:/home$ sudo useradd eric
user@mybox:/home$ userdel eric
userdel: Permission denied.
userdel: cannot lock /etc/passwd; try again later.

sudo gives you the permission to lock it.

user@mybox:/home$ sudo userdel eric
user@mybox:/home$

Look for /etc/group.lock, /etc/passwd.lock and /etc/shadow.lock files and remove them.

Be careful to only remove the files ending in 'lock' or else you might damage your system.

Reference:

Had same issue, since /etc was full. This is why /etc/passwd could not be written. Make sure that you have enough space on /etc, if not then enlarge it or clean unnecessary stuff.