Hi, i just installed VirtualBox on my Debian etch machine. It created a group named 'vboxusers'. When running VirtualBox command from a terminal so that it opens the GUI, i get a message that i am not part of that group. So, i evidently attempted to add the user to that group, using the following command:
adduser -G vboxusers my_user_name
Oddly enough, i get the error message below:
useradd: user ****** exists
Now, performing id 'my_user_name' in the console, i notice that the group vboxusers is not there, which means that i am not a member of that group.

Why is adduser telling me that user exists if i want to add my user to the group??

Thanks in advance for the help.

You should use the usermod command, not useradd to change group membership.

Perhaps you meant to use usermod?

Do you mean something like this?
usermod -a -G vboxusers my_user_name

Try the other way around without "-G": adduser your_user_name vboxusers

Yes, although my version of usermod doesn't support the -a switch. What does it do on your system?

man usermod

That's exactly what i read in the man page for usermod. The command typed in my previous post worked fine. I run an 'id' command on my username and the vboxusers is now listed. According to all the manuals that i found, using useradd was supposed to do the trick, but that's not true. Apparently, on my system, usermod is the way to go.

Thanks a lot for clearing that up for me, i appreciate it.

You are confusing the useradd command with adduser. The latter allows you to add a user to a group. That is what makuyl said but no one paid attention.

It is either adduser username groupname, or adduser groupname username. Check the command line options.

jlinkels