Linux: Group Permissions
Why can't I change permissions on the group I just created?
With the way the CAE system is set up, a user's permissions data and other information is gathered upon logging into a machine. This means that upon creation of a group during a session, the user is not recognized as an owner or member until they log out and then back in again (so chgrp, chown, chmod won't work until that time). Using "sudo" will not work with an average user that is not a CAE administrator.
The solution: Create the group, log out of the Linux machine, then log back in and use the chgrp command to modify permissions.