Microsoft’s Volume Shadow Copy Service (VSS) is Windows’ built-in infrastructure for application backups. As a native Windows service, VSS facilitates creating a consistent view of application data during the course of a backup. VSS relies on coordination between VSS requestors, writers and providers for quiescence, or “to make quiet,” a disk volume, so that a backup can be successfully obtained without data corruption. Native VSS is used to backup VMware and Hyper-V VMs and to restore them to a precise point in time…
AAIP (Application Aware Image Processing = VSS processing of Veeam) allows to ensure application consistence of backup for VSS-Aware applications (SQL, AD, Exchange, SharePoint, Oracle Windows), but also the “File System” consistence for Windows Virtual Machines.
For non-critical Windows Virtual Machines and without VSS-aware applications, you can disable the “AAIP” option and use the “VMware Tools Quiescence” instead. This one ensures at least the coherence of File System.
Basicaly it’s recommended to enable “AAIP” (VSS processing of Veeam) for any Windows VMs and even if there isn’t “VSS-Aware applications” inside. In fact, the VMware mechanisms are limited for this task and sometime they need additional prerequis to work. If you don’t enable the “AAIP” feature or the “VMware Tools Quiescence” option, you will generate a “crash-consistent” backup. It is the same thing that the state of a server after a power outage.
How to check the Volume Shadow Copy Service (VSS) provider/writer status on the VM?
To check the VSS provider/writer status:
- Open a command window. Click “Start”, “Run” and type “CMD”, then click “OK”,
- At the command prompt, type “vssadmin list providers“, and then press ENTER,
- Confirm that the list shows both the Veeam and Microsoft VSS providers listed.