Backing up a virtual machine using HotAdd transport mode fails If SCSI controllers are not added to proper SCSI ports

Products

• VMware vSphere ESXi

Issue/Introduction

Symptoms:

• Taking a backup of virtual machine using HotAdd transport mode fails.
• If SCSI controllers are not added to proper SCSI port, disks do not get hot-added to the proxy machine while taking backup of a Virtual Machine using HotAdd transport mode.

Environment

Virtual Disk Development Kit 6.0
Virtual Disk Development Kit 5.0
Virtual Disk Development Kit 5.1
Virtual Disk Development Kit 5.5

Cause

This issue occurs if the SCSI controller is not added to proper SCSI port. For example, if the first SCSI controller is added at SCSI Port-1 then the second SCSI controller must be added at SCSI Port-2 and third SCSI controller must be added at SCSI Port-3 and so on.

VDDK expects the SCSI Port acquired for each of the SCSI controller to be in order when the initial disks are added to each of those controllers. If the first SCSI controller is added at SCSI Port-2 then during HotAdd mechanism VDDK expects the second SCSI controller to be added in SCSI Port-3 and third SCSI controller to be added in SCSI Port-4 and so on. If the SCSI controllers are not added in the above mentioned order then HotAdd mechanism fails.

To verify that the SCSI controller are added to the proper SCSI port:

1. Click Start > Run., type regedit and click OK.
2. Navigate to Computer\HKEY_LOCAL_MACHINE\HARDWARE\DEVICEMAP\Scsi.

Resolution

To resolve this issue, ensure that the SCSI controllers are added to SCSI ports in order before taking a backup of a virtual machine using HotAdd transport mode.

For example:

If the first SCSI controller is added at SCSI Port-1 then the second SCSI controller must be added at SCSI Port-2 and third SCSI controller must be added at SCSI Port-3. If the first SCSI controller is added at SCSI Port-2 then during HotAdd mechanism VDDK expects the second SCSI controller to be added in SCSI Port-3 and third SCSI controller to be added in SCSI Port-4 and so on.

Additional Information

Impact/Risks: