I received a call from a customer yesterday in need of a little help. They had installed a Comtrol Rocketport multiport serial card into an ESX 3.o.1 server and were attempting to use with some test VMs. When they tried to add the devices “/dev/ttyRX” there was no option to do this in Virtual Center.

When you add a serial port to a VM, you receive 3 options. You can configure the virtual serial port to communicate over a physical port, a “pipe”, or a file. (In UNIX and Linux, everything is a file.) The customer had tried using a “pipe”, they had tried specifying the device file name in the file option, and since the appropriate devices were not listed in the physical port option the customer was at a loss.

In the end, the answer was simple. Use Virtual Center to create the virtual serial port and attach it to one of the standard “/dev/ttySX” devices. Then, before powering on the VM, go into that VM’s *.vmx file and modify the serial port config line so that it uses the correct “/dev/ttyRX” port.

As for configuring the Comtrol Rocketport in the Service Console, I wasn’t privvy to how they did that. I do know that they had to manually install the proper module.

I hope this helps someone out.