Quiesced snapshot of a Windows 2008/2012 R2 using GPT creates a ghost partition

Products

• VMware vCenter Server
• VMware vSphere ESXi

Issue/Introduction

Symptoms:

• A Windows 2008 R2 and Windows 2012 R2 guest operating system shows ghost volumes after the first quiesced snapshot.
• When a quiesced snapshot of a virtual disk (vmdk) is taken, a third partition is created on the virtual disk.
• An extra GPT partition displays in Disk Management.
• The third partition is 256 KB in size and of type unknown.
• Virtual machine backups fail.

Environment

VMware vSphere ESXi 7.0.0
VMware vSphere ESXi 6.5
VMware vSphere ESXi 5.5
VMware vCenter Server 5.5.x
VMware vSphere ESXi 6.7
VMware vCenter Server 5.1.x
VMware vSphere ESXi 5.1
VMware vSphere ESXi 6.0

Cause

This issue occurs when the IOCTL operation is used. Disk Management tools report an additional partition of the type UNKNOWN on GPT disks. It is a 256 KB snapshot partition and used in the restore process.

 

For more information, see the Microsoft Dev Center article IOCTL_DISK_RESET_SNAPSHOT_INFO control code.

Resolution

The additional partition of the type UNKNOWN on GPT disks is an expected behavior and can be safely ignored.