Add a Serial Port to a Virtual Machine

You can connect the virtual serial port to a physical serial port or to a file on the host computer. You can also use a host-side named pipe to set up a direct connection between two virtual machines or a connection between a virtual machine and an application on the host computer. In addition, you can use a port or vSPC URI to connect a serial port over the network. A virtual machine can use up to 32 serial ports.

Important: With virtual hardware version 11 and later, if you configure a virtual machine without serial ports, they are entirely removed from the virtual chipset and they are not visible to the virtual machine OS.

Prerequisites

• Verify that the virtual machine is powered off.
• Check that you know the correct media types for the port to access, vSPC connections, and any conditions that might apply. See Using Serial Ports with vSphere Virtual Machines.
• To connect a serial port over a network, add a Firewall rule set. See Adding a Firewall Rule Set for Serial Port Network Connections.
• To use authentication parameter with network serial port connections, see Authentication Parameters for Virtual Serial Port Network Connections.
• Required privilege: Virtual Machine .Configuration.Add or Remove Device

Procedure

1. Right-click a virtual machine in the inventory and select Edit Settings.
2. On the Virtual Hardware tab, add a new network adapter.

   Client	Steps
   vSphere Client	Click the Add New Device button and select Serial Port from the drop-down menu.
   vSphere Web Client	Select Serial Port from the New device drop-down menu at the bottom of the wizard. Click Add.

   The new serial port appears at the bottom of the device list.
3. From the New Serial port drop-down menu, select a connection type.

   Option	Action
   Use physical serial port	Select this option to have the virtual machine use a physical serial port on the host computer. Select the serial port from the drop-down menu.
   Use output file	Select this option to send output from the virtual serial port to a file on the host computer. Browse to select an output file to connect the serial port to.
   Use named pipe	Select this option to set a direct connection between two virtual machines or a connection between a virtual machine and an application on the host computer. To prevent connectivity failure, configure the virtual machine that powers on first as a server and the next virtual machine as a client. Type a name for the pipe in the Pipe Name field. Select the Near end and Far end of the pipe from the drop-down menus.
   Use Network	Select Use network to connect through a remote network. Select the network backing. Select Server to have the virtual machine monitor incoming connections from other hosts. Select Client to have the virtual machine initiate a connection to another host. Enter a Port URI. The URI is the remote end of the serial port to which the virtual machine's serial port should connect. If vSPC is used as an intermediate step to access all virtual machines through a single IP address, select Use Virtual Serial Port Concentrator and enter the vSPC URI location.

4. (Optional) Select Yield CPU on poll.
   Select this option only for guest operating systems that use serial ports in polled mode. This option prevents the guest from consuming excessive CPUs.
5. (Optional) Select Connect at power on to connect the serial port when the virtual machine powers on.
6. Click OK.

Example: Establishing Serial Port Network Connections to a Client or Server Without Authentication Parameters

If you do not use vSPC and you configure your virtual machine with a serial port connected as a server with a telnet://:12345 URI, you can connect to your virtual machine's serial port from your Linux or Windows operating system.

telnet yourESXiServerIPAddress 12345

Similarly, if you run the Telnet Server on your Linux system on port 23 ( telnet://yourLinuxBox:23), you configure the virtual machine as a client URI.

telnet://yourLinuxBox:23

The virtual machine initiates the connection to your Linux system on port 23.