CVM enters into cyclic boot and PCIPassthru configuration on the CVM is lost

Products

• VMware vSphere ESXi
• VMware vSphere ESX 6.x

Issue/Introduction

• Nutanix CVM enters into a cyclic boot loop.

• Unable to find PCI Passthrough device in CVM machine settings.

• CVM machine edit settings page returns error: "There are no devices reserved for PCI passthrough on the host."

• Validating the host passthrough configuration page under Configure > Hardware > PCI Devices displays the following error: "This device is not currently available for VMs to use."

Environment

VMware vSphere ESXi 6.7

Cause

• This issue occurs because the Memory Reservation setting on the CVM is not configured. When a PCI device is added to a virtual machine, the full memory size of the virtual machine must be reserved to ensure proper functionality. Without memory reservation, the passthrough device cannot be properly assigned to the CVM, leading to the cyclic boot issue and device unavailability.

 

Resolution

To resolve this issue, follow these steps:

1. Ensure PCI Device is Added and Configured Correctly on the Host

   1. The PCI device status should display as "Available."

   2. When selecting the device, it should indicate "This device is available for VMs to use."

   3. If the device is not available, click Refresh or CONFIGURE PASS THROUGH again.

   Path: Host > Configure > Hardware > PCI Device
   
   
   

2. Add PCI Device on CVM Machine

   1. Right-click the CVM machine.

   2. Click Edit Settings > Add New Device > PCI Device.

   
   
   

3. Reserve the Memory for the CVM

   1. Navigate to the Memory settings of the CVM.

   2. Enable Memory Reservation for the full allocated memory.

   
   
   

4. Power On the CVM Virtual Machine

   1. Start the CVM and verify that the PCI passthrough device is detected correctly.
      
      
      

Following these steps should resolve the cyclic boot issue and restore PCI passthrough functionality on the CVM.