Unable to Add vNIC to Powered-On Virtual Machine Due to Disabled Hot-Plug

Products

• VMware vSphere ESXi

Issue/Introduction

An administrator is unable to dynamically add a virtual network adapter (vNIC) to a powered-on Virtual Machine.

The operation fails or the option to add the network adapter is unavailable or restricted during the powered-on state.

Cause

The PCI hot-plug subsystem has been explicitly disabled at the Virtual Machine configuration level via the devices.hotplug = "false" advanced parameter. This setting disables the entire PCI hot-plug architecture, preventing the dynamic addition of hardware while the Guest OS is actively running.

Resolution

1. Power off the affected Virtual Machine.

2. Right-click the Virtual Machine and select Edit Settings.

3. Navigate to the VM Options tab and expand the Advanced section.

4. Click Edit Configuration.

5. Locate the devices.hotplug parameter in the list.

6. Change the value of devices.hotplug from false to true, or remove the entry entirely.

7. Click OK to save the advanced configuration changes.

8. Click OK to close the Edit Settings window.

9. Power on the Virtual Machine.

10. Proceed to hot-add the vNIC to the powered-on Virtual Machine.

Additional Information

• Disabling the HotAdd/HotPlug capability in virtual machines
• Add a Network Adapter to a Virtual Machine