When installing FreeBSD, if you forget to assign your user to the wheel group, you wont be able to switch to the root user using the su command.
When running su, with a user that not in the wheel group, the following output is produced:
What’s worse, is since you cant switch to root, you wont be able to add the current user to the wheel group.
This post will show you an easy way to fix the problem.
Solving the FreeBSD “su: Sorry” Problem
The solution is to restart FreeBSD in single user mode and then make the change as root. This can be done by following the steps below:
Step 1: Restart the server, then press 2 to boot into single user mode.
Step 2: Make the file system writable by running the following command:
mount -u -w /
Step 3: Assuming your user is called sysadmin, run the following command to add the user to the wheel group:
pw usermod sysadmin -G wheel
Step 4: Restart the server and test the su command.
As you can see from the output above, the su command now switches to the root user account when running it as the sysadmin user.