Virtual Device Serial0 Will Start Disconnected May 2026

This warning message (or log entry) typically appears in VMware products (like VMware Workstation, Player, or ESXi). It indicates that the virtual machine is configured to have a serial port, but the host computer cannot connect to it—usually because the designated file or device path does not exist yet.

Decoding "Virtual Device Serial0 Will Start Disconnected": Causes, Fixes, and Best Practices

If you have ever fired up a Cisco router in Dynamips, GNS3, EVE-NG, or Cisco Packet Tracer, you have likely seen the console output slowly crawl by until it halts at a seemingly concerning line: virtual device serial0 will start disconnected

This message typically appears in virtual machine platforms (like VMware, VirtualBox, or QEMU) or network simulation tools (like GNS3 or EVE-NG). This warning message (or log entry) typically appears

Understanding "Virtual Device Serial0 Will Start Disconnected"

The message indicates that the virtual device associated with serial0 (the first virtual serial port in many virtualization platforms) is not connected when the VM starts up. This disconnection can occur for several reasons: loop until host socket exists or QMP reports

: For persistent network-backed serial port issues in vSphere, adding the parameter vpxd.SerialPort.PersistNetworkBacking = "True"

• loop until host socket exists or QMP reports chardev attached; then open serial console.

) to handle "Virtual Printing" (ThinPrint). Following the removal of this feature in late 2023 updates, legacy virtual machine configurations still contain entries for it, leading to an invalid parameter error: serial0.fileType = "thinprint" How to Resolve the Issue Method 1: Using the GUI (Recommended for Workstation) Power off the virtual machine. VM Settings Select the and save your changes. : In VMware Workstation, go to Preferences and uncheck "Enable virtual printers" to prevent it globally. Broadcom support portal