Windows Backup Implementations

The following sections discuss issues when backing up Windows virtual machines.

Disable Automount in Windows Proxy
When using HotAdd transport from a Windows proxy, it can make unwanted changes to HotAdded volumes. To prevent this, backup vendors and customers should disable Windows automount on the backup proxy.
Security and Remote Desktop
For security reasons, remote desktop protocol (RDP) should be disabled on a Windows proxy.
Working with Microsoft Shadow Copy
Microsoft Shadow Copy, also called Volume Snapshot Service (VSS), is a Windows Server data backup feature for creating consistent point-in-time copies of data (called shadow copies).
Enable Virtual Machine Application Consistent Quiescing
To enable virtual machine application consistent quiescing on Windows 2008 or later:
Application-Consistent Backup and Restore
Here is the approximate procedure for software to performs application-consistent backup and restore:
New VSS Support Added in vSphere 6.5
The vSphere 6.5 release includes additional volume shadow-copy service (VSS) configurations and features. To support these new configuration and for more granular control over Windows guest OS quiescing, the function CreateSnapshotEx_Task was added to the 6.5 vSphere API, superseding CreateSnapshot_Task. CreateSnapshotEx_Task takes a quiesceSpec parameter, of type VirtualMachineGuestQuiesceSpec or VirtualMachineWindowsQuiesceSpec. The latter type can specify several important fields such as:
The VMware VSS Implementation
As of Windows Server 2008, disk UUIDs must be enabled for VSS quiesced snapshots. Disk UUIDs might not be enabled if a virtual machine was upgraded from virtual hardware version 4.

Parent topic: Backing Up Virtual Disks in vSphere