Error message id: cannot find name for group ID after logging in

BACKGROUND

Trevor logs into his account on ssh://foobar.university.edu as one of the developers on the box, and he gets the message:

 id: cannot find name for group ID 131

Trevor then checks this out using

 vim /etc/group

PROBLEM

Trevor discovers that there is no 131 anywhere in the /etc/group file.

Trevor then runs id …

 > id trevor
 uid=4460(trevor) gid=131 groups=48(foobar),51(doobar),131

To discover his primary group apparently does not have a name attached to it.

QUESTIONS

  • What likely happened to cause this circumstance on the foobar.university.edu box ?
  • Suppose trevor wants to fix this (e.g., by just creating a “trevor” group that maps to GID 131) what is the best way to do this without potentially breaking anything else on the server ?
Asked By: dreftymac

||

What likely happened is that the UID and GID are provided to the server via LDAP. If the /etc/group file doesn’t contain the translation for the GID, then the server administrators likely just failed to update the group definitions. What can you do? Not much. The user id is controlled by the administrator. (Now if you happen to have ROOT privileges, you can add the group into /etc/group. You should also check to see if any other user accounts are using the same group, and if they are, name the group appropriately).

Answered By: sparticvs

This happened when my user “jackson” wasn’t assigned a group. I knew the solo group id for my user was 1000 (when a user is created with $ adduser and no parameters are defined, the user is assigned the next ids available beyond 999. The first getting uid 1000 and gid 1000).

This warning means your user does not belong to a group so what you need to do is to add the user to a group. Either have your admin help you like @sparticvs mentioned or if you have root privileges / it’s your machine you can do the following:

$ addgroup [your_user_name]
$ usermod -a -G [your_user_name] [your_user_name]

And that should fix it (untested)

What I did was simply (advanced)

  • $ sudo vi /etc/group
  • modify the line of web:x:1001: to web:x:1000:jackson

Which made my user jackson belong to the web group.

FYI if you’re not familiar with vim I do not recommend the “advanced” steps, if you’re really really desperate use $ sudo nano /etc/group

Answered By: Jacksonkr

This can also happen if you are running a VM that usually gets its data from LDAP, but is unable to connect. I’m sure that there’s a way to fix this, but I usually just reboot it once the connection is available again.

Answered By: gbronner

Similar issue but with ad authentication. How to solve:

systemctl stop winbind
systemctl stop smbd.service
net cache flush
rm /var/lib/samba/*.tdb
systemctl start smbd.service
systemctl start winbind.service

logon again and problem solved.

How to clear winbind cache: http://raafat.tawasol.net/clear-winbind-cache/

Answered By: dorancemc

If you are using AD to authenticate, could be that in sshd config you do not have enabled parameter auto_private_groups = true and after login OS is not able to create private gorup what is neede to chmod /home/user to correct permissions. Check:

[domain/YOUR_DOMAIN]
...
# https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/windows_integration_guide/gid-for-ad-users
# virtual private groups
auto_private_groups = true

than restart sssd and re-login.

Answered By: dwa6
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