Инструменты доступности

Disconnected: Virtual Device Serial0 Will Start

This message typically appears in VMware Workstation or VMware Fusion when a virtual machine (VM) is configured to look for a serial port that is unavailable, invalid, or belongs to a legacy feature no longer supported. Why it Happens

Legacy "ThinPrint" Service: Recent versions of VMware (Workstation 17.5+ and Fusion 13.5+) have removed the ThinPrint virtual printing feature. If your VM was created in an older version, it might still try to initialize a virtual serial port (serial0) specifically for this printer service.

Missing Physical Hardware: The VM is set to connect to a physical COM port on your host machine that does not exist or is currently being used by another application.

Invalid Configuration: The .vmx configuration file contains parameters for serial0 that the hypervisor cannot process, such as an invalid file type or destination. How to Fix It Method 1: Disable Virtual Printing (Recommended)

Since the most common cause is the deprecated ThinPrint service, removing the virtual printer often stops the message. Shut down the virtual machine. Go to Virtual Machine Settings. Look for Virtual Printer in the device list. Select it and click Remove. Restart the VM to see if the message persists. Method 2: Manually Edit the .vmx File

If the device doesn't appear in the standard settings menu, you can remove it directly from the configuration file. Shut down the VM and close VMware.

Navigate to the folder where your VM is stored and locate the .vmx file. Open it with a text editor (like Notepad).

Search for lines starting with serial0 and either delete them or change their values to FALSE: serial0.present = "FALSE"

Remove lines like serial0.fileType = "thinprint" and serial0.fileName = "thinprint". Save the file and restart VMware. Method 3: Reconfigure the Serial Port

If you actually need a serial port (e.g., for debugging), ensure it is mapped to a valid resource. Go to Edit Settings > Serial Port.

Ensure it is mapped to a valid Physical serial port, Output file, or Named pipe.

If you aren't using it, simply uncheck Connect at power on to hide the warning while keeping the device in your configuration. virtual device serial0 will start disconnected

Virtual Device Serial0 Will Start Disconnected - Google Groups

Troubleshooting VMware: "Virtual device serial0 will start disconnected"

If you’ve recently powered on a VMware Workstation or ESXi virtual machine only to be greeted by the warning message "Virtual device serial0 will start disconnected," you aren’t alone. This is a common configuration hiccup that occurs when a VM is looking for a physical or virtual serial (COM) port that the host system can’t provide.

While it usually doesn’t prevent the guest OS from booting, it can be an annoying hurdle—especially if you need console access or simply want a clean, error-free startup. Why is this happening?

At its core, this error means the Virtual Machine settings include a Serial Port hardware device, but the "Backing" (the physical resource it’s supposed to connect to) is missing or busy. Common culprits include:

Missing Physical Ports: Your VM is configured to use "Physical Serial Port COM1," but your modern laptop doesn't actually have a 9-pin serial port.

Disconnected Pipes: The VM is set to use a "Named Pipe" for debugging, but the other end of the pipe isn't active.

Conflict: Another application or VM is already using the host's COM port.

Legacy Templates: You cloned a VM from an older template that included serial hardware by default. How to Fix "Serial0 Will Start Disconnected"

Depending on whether you actually need the serial port or just want the error to go away, use one of the following three methods. Method 1: Remove the Serial Port (Recommended)

Most modern operating systems (Windows 10/11, standard Linux distros) do not require a serial port to function. If you aren't doing low-level kernel debugging or connecting to industrial hardware, the easiest fix is to delete the device. Shut down the virtual machine. Right-click the VM and select Settings. Go to the Hardware tab. Locate Serial Port (or Serial0) in the list. Click Remove. Click OK and restart the VM. Method 2: Disconnect at Power On This message typically appears in VMware Workstation or

If you think you might need the port later but want to stop the error message now, you can tell VMware to ignore it during boot. Go to VM Settings > Hardware. Select Serial Port.

Under the "Device status" section, uncheck Connect at power on.

This keeps the hardware in your configuration but prevents VMware from trying (and failing) to initialize it during startup. Method 3: Point to an Output File

If you are a developer or sysadmin who needs the data from that serial port, you can redirect the "Serial0" output to a text file on your host machine instead of a physical port. In VM Settings, select the Serial Port. Change the connection type to Output to file.

Browse to a location on your host and create a .txt or .log file.

Click Save. Now, anything the VM sends to the serial port will be recorded in that file without triggering a connection error. Still seeing the error?

If the error persists or the settings won't save, you may need to manually edit the VM's configuration file: Navigate to the folder where your VM is stored. Open the .vmx file with Notepad. Look for lines starting with serial0.

Change serial0.present = "TRUE" to serial0.present = "FALSE". Save the file and reload the VM in VMware.

The "virtual device serial0" error is rarely a "broken" VM; it’s just a mismatch between virtual hardware and physical reality. By removing the port or disabling the "Connect at power on" toggle, you can return to a seamless, one-click boot process.

Are you using this serial port for kernel debugging or just trying to get a clean boot?

This warning message, "virtual device serial0 will start disconnected", is one of the most common errors seen by users of VMware Workstation, VMware Player, and VMware Fusion. Common Scenarios Where This Warning is Misinterpreted Step

It typically appears as a pop-up window immediately after you power on a virtual machine (VM). While it often looks like a critical error, it is usually just a configuration notification.

Here is your complete guide to understanding, fixing, and silencing this message.

Common Scenarios Where This Warning is Misinterpreted

Step 4: Verify via .vmx File

You can also edit the VMX file directly (with VM powered off):

Look for lines like:

serial0.present = "TRUE"
serial0.startConnected = "FALSE"

Change to:

serial0.startConnected = "TRUE"
serial0.fileType = "file"
serial0.fileName = "nul"

Or to remove completely:

serial0.present = "FALSE"

2. Scenario A: You NEED the Serial Port (For Debugging/Logging)

If you are a developer or network engineer using the serial port for OS debugging, kernel logging, or GNS3/VMware communication, you need to fix the connection path.

For VMware Workstation / Player:

  1. Power off the Virtual Machine.
  2. Go to VM > Settings.
  3. Click on the Serial Port (Serial0) in the hardware list.
  4. Check the configuration:
    • Use Output File: Ensure the path is valid. If the file doesn't exist, browse to a valid directory and type the filename (e.g., debug.txt). VMware will create it upon boot.
    • Use Named Pipe: Ensure the pipe name is correct (e.g., \\.\pipe\com_1). If this is for GNS3 or dynamips, ensure the other application is running before starting the VM.
  5. Check the box "Connect at power on".
  6. Click OK and start the VM.

For ESXi / vSphere:

  1. Edit the VM Settings.
  2. Select the Serial Port.
  3. If using a file path, ensure the datastore path is valid (e.g., [Datastore] VMname/serial.out).
  4. If using a physical serial port on the host, ensure the passthrough configuration is correct in the host's "PCI Devices" settings.

Where this message appears

Solution 3: Command Line (Manual NET File Editing)

If you are a hardcore Dynamips user on Linux, you can edit the .net file directly. Change this:

[[router R1]]
    image = c7200.bin
    serial0 = "disconnected"

To this:

[[router R1]]
    image = c7200.bin
    serial0 = "R2 serial0"

This tells Dynamips to create a direct serial cable between the two virtual devices on boot.

5. Default on Newly Created VMs

Some VM templates or quick-creation wizards add a serial port by default but leave it disconnected. This is common in Linux VM templates that include a legacy console serial port that may not be needed.

Is this an error? No.