3.5.4. Modifying Group Settings

When a group already exists and you need to specify any of the options now, use the groupmod command. The logic of using groupmod is identical to groupadd as well as its syntax:
groupmod option(s) groupname
To change the group ID of a given group, use the groupmod command in the following way:
groupmod -g GID_NEW which_group_to_edit


Find all files owned by the specified GID in system and change their owner. Do the same for Access Control List (ACL) referring to the GID. It is recommended to check there are no running processes as they keep running with the old GID.
To change the name of the group, run the following on the command line. The name of the group will be changed from GROUP_NAME to NEW_GROUP_NAME name.
groupmod -n new_groupname groupname

Example 3.21. Changing a Group's Name

The following command changes the name of the group schoolmates to crowd:
~]# groupmod -n crowd schoolmates