m8fyu
By:
m8fyu

sudo: unknown user: root - please help!

November 25, 2014 8.5k views

I was using terminal, and vim, to edit my /etc/passwd file and got a 'broken pipe' message in the window. I have CentOS

When I logged back onto the server I tried to access the file again using sudo.

I got the following:
sudo: unknown user: root
sudo: unable to initialize policy plugin

I can open the file without sudo, and notice there are a couple of lines that were at beginning of the list that have disappeared - Luckily I've been keeping a 'diary' of what I've been doing over the past couple of months so have a print-out of the contents of passwd.

The missing lines are:
root:x:0:0:root:/root:/bin/bashing
bin:x:1:1:bin:/bin:/sbin/nologin:

I'm able to copy the missing lines back but the file won't save.

At the bottom of the window I see:
"/etc/passwd" [readonly] 29L, 1454C

When I hit 'ESC :wq' I see:
E45: 'readonly' option is set (add ! to override)

I've tried all manner of ways including ':w !sudo tee %' to try to get this file to save but to no avail.

I also discovered another warning that momentarily displayed then disappeared. I managed to get a screen shot of it.

E325: ATTENTION
Found a swap file by the name "var/tmp/passwd.swp"
...
While opening file "/etc/passwd"

(1) Another program may be editing the same file.
...

(2) An edit session for this file crashed.
If this is the case, use ":recover" or "vim -r /etc/passwd"
to recover the changes (see ":help recovery").
If you did this already, delete the swap file "/var/tmp/passwd.swp"
to avoid this message.

Can anyone give me any suggestions please? I've spent all day trying to figure it out but I'm fairly new to all this.

1 comment
  • Why do you edit passwd file? there are commands to add/modify/delete users, that is very dangerous as you now can see.

    Are you login as root or as a different user?, is you are login with another user the su command works?

    If you can login as root via ssh you should not need to "sudo vim ... ", if you can't access as root at all, then you have a really big problem. There is any other root like user in your droplet, one you granted root like access to?

1 Answer

Hi, and thank you for answering.

I followed a tutorial to set up the server and I think I did set up a new user with root privileges. I also changed the SSH default port and disabled root login.

I log on to the server like so - newusername@123.456.789. However I've always needed to use sudo to make changes so I assume that I didn't set up the new user privileges correctly.

I just tried: /usr/sbin/visudo

I get this message: visudo: /etc/sudoers: Permission denied

I think I have a really big problem, like you say. What is the solution if I can't access root?

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