Mastering Proxmox - Third Edition

Issue – virtual machines on Proxmox will not shut down if shutdown is initiated from the Proxmox GUI

This issue is not consistent and is not directly related to Proxmox. The Shutdown button on Proxmox's GUI only sends an ACPI signal to a virtual machine to initiate the shutdown process.

Once the VM receives an ACPI signal, it starts the shutdown process. However, if the VM has a number of processes running in the memory, it might take a while to end processes before shutdown. The ending of processes may take longer, which causes Proxmox to issue a timeout error. The issue may occur for both Windows and Linux. The workaround for this is to access the VM through a console or SPICE and then manually shut down the VM.