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

Products

• VMware vCenter Server
• VMware vSphere ESXi

Issue/Introduction

• 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
• 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.