On our 'new' X4540 we use a serial console. This has a few advantages:

  • It's easy to access with just ssh -- no X11 or VNC tunneling required, unlike the Java-based graphical console.
  • It's much faster & more efficient (quite usable over dial-up, which shockingly is not yet dead).
  • Serial output gets logged to our console server, so we have a record of some diagnostics.

On SPARC systems at Rockefeller, we simply didn't connect a USB keyboard -- the console automatically went to the serial port. To login to a Sun from the machine room, we used a Linux or PC as a terminal.

Here, though, we also want access to (x86-based) Suns via the local KVM switch, which is slightly more complicated.

Supposedly, installing in serial mode enables serial console, but I couldn't confirm this. dtconfig controls the graphical login prompt, but shouldn't be needed.

Basically I just had to run eeprom console=ttya and reboot to move the console to serial port A. This didn't interfere with graphical login.

Kernel arguments in /boot/grub/menu.lst, if specified, can override eeprom, which is how 'failsafe' boot (from the GRUB menu) works.