Linux 2.6.x kernels that support parallel ports use the modprobe modulename and modprobe parport_pc modules. Workstation Pro requires that the parallel port PC-style hardware option (CONFIG_PARPORT_PC) is built and loaded as a kernel module.

Linux kernels in the 2.6.x series use a special arbitrator for access to the parallel port hardware. If the host system is using the parallel port, the virtual machine cannot use it. If a virtual machine is using the parallel port, the host and any users accessing the host are denied access to the device. You must use the Removable Devices menu to disconnect the parallel port from the virtual machine to access the device from the host system.

Procedure

  1. To determine whether the modprobe modulename and modprobe parport_pc modules are installed and loaded on the host system, run the lsmod command as the root user.

    You can also see a list of modules in the /proc/modules file.

    Note: In Linux 2.6.x, loading parport_pc does not load all modules.
  2. If necessary, load the parallel port modules.
    For example: modprobe parport_pc && modprobe ppdev
    This command inserts the modules that are required for a parallel port.
  3. If the lp module is loaded, run the rmmod command as root to remove it.
    For example: rmmod lp
    The virtual machine cannot use the parallel port correctly if the lp module is loaded.
  4. Comment out the line that refers to the lp module in the /etc/modules.conf or /etc/conf.modules file.
    The name of the configuration file depends on the Linux distribution.
    When the line is commented out, the configuration file no longer starts the lp module when you reboot the host system.
  5. To make sure that the proper modules for the parallel port are loaded at boot time, add the following line to the /etc/modules.conf or /etc/conf.modules file.
    alias parport_lowlevel parport_pc