0%
This is very common for network emulation users. GNS3 often links virtual routers to VMware VMs via named pipes for console access.
The Fix:
When a virtual machine starts with the warning "Virtual device serial0 will start disconnected," it typically means the VM is trying to initialize a serial port that is either misconfigured, pointing to a non-existent physical resource, or linked to a legacy feature that is no longer supported. Core Causes of the Warning
ThinPrint Feature Removal: The most common reason in modern versions of VMware Workstation (17.5+) and VMware Fusion (13.5+) is the removal of the ThinPrint virtual printing feature. These newer versions no longer support the ThinPrint protocol, which often utilized serial0.
Missing Host Resources: The VM configuration might be set to map serial0 to a physical COM port on the host machine that is currently in use by another application or simply does not exist.
Disconnected on Power On: The "Connect at power on" option for the serial device may be unchecked in the VM settings, triggering a notification that it will remain inactive. How to Resolve the Warning virtual device serial0 will start disconnected
Depending on your needs, you can either remove the device entirely or reconfigure it to clear the error. Option 1: Remove the Printer Device (Recommended)
If you do not explicitly use virtual printing, removing the legacy device is the cleanest fix. Power off the virtual machine completely. Open Edit Virtual Machine Settings.
Select the Printer or Serial Port device associated with serial0. Click Remove and save the changes. Option 2: Edit the VMX Configuration File
For advanced users or situations where the GUI does not show the device (common in Fusion or Workstation updates), you can manually remove the entries from the .vmx file.
Locate your VM's folder and open the .vmx file with a text editor. Find and delete the following lines if they exist: serial0.fileType = "thinprint" serial0.fileName = "thinprint" serial0.present = "TRUE" Save the file and restart the VM. Option 3: Disable "Connect at Power On" This is very common for network emulation users
If you want to keep the device but stop the warning, you can tell VMware not to attempt a connection during boot.
In the VM settings, go to the Serial Port section and uncheck Connect at power on. This will stop the system from checking for the resource every time it starts. Why this happens with Printers
Legacy VMware versions automatically added a virtual printer that used a virtual serial port to communicate with host drivers. Because Broadcom/VMware discontinued ThinPrint, the software identifies a device it can no longer operate, resulting in the "start disconnected" status. AI responses may include mistakes. Learn more VMware Cannot Connect the Virtual Device sata0:1 Error
The resolution depends on your specific needs and configuration:
In conclusion, a "virtual device serial0 will start disconnected" message alerts you to a configuration or connectivity issue affecting a VM's virtual serial port. By understanding the implications and following systematic troubleshooting steps, you can resolve the disconnection and ensure that serial communication functions as needed within your virtual environment. When a virtual machine starts with the warning
If the UI options do not fix the issue, you may need to edit the VM's configuration file directly.
serial0.fileName = "C:\VM\Logs\serial_output.txt"
(Note: Ensure the folder exists, or VMware will fail to connect).For most users: No. The warning is completely harmless.
For certain users: Yes, you need to address it.
You should fix this if: