Virtual Device Serial0 Will Start Disconnected 2021 -

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.

The statement “virtual device serial0 will start disconnected” typically appears in virtualization, emulation, or hardware abstraction contexts (e.g., QEMU/KVM, VirtualBox, containerized device passthrough, or network/device simulators). It means the emulated or virtual serial interface named serial0 is configured so that, at VM or system boot, it has no active connection endpoint—no host pipe, socket, file, console, or physical device attached. The device exists in the guest’s device tree but is not linked to any I/O endpoint until explicitly connected. virtual device serial0 will start disconnected