Mac OS X Server 10.0: Blue Flashing Screen at Login Window

Symptom

During startup, the server stops responding at the Login Window. You see a flashing blue screen.


Solution

This occurs if you change the privileges on the root level of the server's startup disk to take away read access for "Everyone." Follow these steps to resolve this issue:

1. Shut down the computer.
2. Press the power key and then immediately press and hold the Command (Apple) and V keys. This will cause the computer to start up in verbose mode.
3. Open the Server Admin application from another computer, which must have a TCP/IP route to the server.
4. Connect to the server using Server Admin.
5. Click the General tab and then choose Set Sharing Attributes from the Sharing module menu.
6. Select the server's startup disk and set the privileges for Everyone to "Read only."
7. Restart the server.
Note: You may use an SSH connection ("sudo reboot" command) from the Admin computer to restart the server, or perform a force restart using the reset button at the server.