Sometimes, during the backup process, some Volume Shadow Copy service writers might fail because of time-out errors that cause the backup to fail. A Volume Shadow Copy service writer is a program or a service that uses Volume Shadow Copy service to save information to a shadow copy storage area.

In this scenario, the backup task fails, and you may receive the following error message that states the Volume Shadow Copy Service (VSS) failed because of a time-out:

Assume that some Volume Shadow Copy Service (VSS) backup operations are running at the same time in Microsoft SQL Server 2008 R2, SQL Server 2012, or SQL Server 2014. Additionally, assume that the auto-recovery option is enabled. In this situation, the backup operations are not successful.

When a VM is up and running, the size of the .vmrs file is equal to that of the configured RAM of the VM. When you back up the VM, the Hyper-V Volume Shadow Copy Service (VSS) writer also returns the .vmrs file as the file to be backed up.

This article describes an issue that occurs when you use the Volume Shadow Copy Service (VSS) backup on a Cluster Shared Volumes (CSV) volume by using a software snapshot provider in Windows Server 2012 R2 or Windows Server 2012.

Fixes an issue in which volume shadow copy operations fail and you receive a "VSS_E_PROVIDER_VETO" error message in Windows Server 2008 or Windows Storage Server 2008. This issue occurs if you try to create VSS backups of multiple volumes and if the size of one of the volumes is large.

When you try to perform system state backups on the passive node of the CCR clusters, you receive the following error message: Failure in a Volume Shadow Copy Service operation.

Fixes an issue in which VSS snapshot restore fails in Windows Server 2012.

During a move of the Physical Disk resource, when the Physical Disk resource comes online on the new node, the Physical Disk resource queries the Volume Shadow Copy Service (VSS) to discover the software snapshots that are associated with that volume.

Assume that you have a database that has a case-sensitive collation in Microsoft SQL Server 2012 Service Pack 2 (SP2). When you try to back up AlwaysOn secondary databases by using Volume Shadow Copy Service (VSS), you may receive the following messages in the Windows Application log: