Configuring a Serial Port

Select: VM > Settings > Hardware > Serial

A virtual machine can use up to four virtual serial ports. The virtual serial port can connect to a physical serial port or to a file on the host operating system. It may also be used to set up a direct connection between two virtual machines or a connection between a virtual machine and an application on the host computer.

You can set the following options under Device status:

Connected — Check or uncheck this option to connect or disconnect the drive while the virtual machine is running.
Connect at power on — Check this option if you want the drive to be connected automatically whenever you power on the virtual machine. You can change this setting when the virtual machine is powered on or powered off.

You can set the following options under Connection:

Use a physical serial port — Select this setting if you want the virtual machine to use a physical serial port on the host computer. Use the drop-down list to specify which available parallel port to use.
Note: If you are connecting with a Windows console to add a physical serial port to a virtual machine on a remote Linux host, be sure to specify a Linux device name here, such as /dev/ttyS0. If you are connecting with a Linux console to add a physical serial port to a virtual machine on a remote Windows host, be sure to specify a Windows device name here, such as COM1.
Use output file — Select this setting if you want to send output from the virtual serial port to a file on the host computer. Type the path and filename for the file or click Browse to locate an existing output file.
Use named pipe — Select this setting 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 the first field, enter /tmp/<socket> or another Unix socket name of your choice. The pipe name must be the same on server and client.
Note: If you are using a Windows console to connect to a virtual machine on a remote Linux host, be sure to specify a Linux pipe name here, such as /tmp/ <pipe>. If you are using a Linux console to connect to a virtual machine on a remote Windows host, be sure to specify a Windows pipe name here, such as \\.\pipe\<namedpipe>.
In the first drop-down list, choose whether this is the server or the client.
In the second drop-down list, choose whether the other end is a virtual machine or an application.

Under I/O Mode, you may select Yield CPU on poll. This setting can improve performance when the guest operating system is using the serial port in polled mode. If the guest operating system is using the serial port in interrupt mode, do not select this option.

If you are adding a new serial port, click Add to install the device.

To remove an existing serial port, select that port, then click Remove.

Click OK to save the configuration and close the virtual machine settings editor.