The Volume Shadow Copy Service (VSS) is the key to ensuring application consistency on Windows systems. The VSS is essentially a framework between the operating system and an application and a means to quiet the application, which is usually to perform a backup. For most Microsoft applications, such as Microsoft SQL Server and Exchange, a Volume Shadow Copy writer is in place to interact with the VSS.
The vssadmin tool is a command-line utility to interact with the VSS. The vssadmin utility is essentially a window into all aspects of the VSS for the running system -- this includes current shadow copy backups, installed shadow copy writers, and providers. The provider can be either the built-in Microsoft Windows provider or at a lower level such as at a drive array. HP storage products and most other mainstream storage products feature a VSS provider from the array level.You should inspect the current VSS configuration on a Windows server by running the vssadmin tool. A number of commands can be used to inspect the configuration. As a general rule, stick to the "list" commands to inspect the configuration on a Windows server with a minimal configuration. Figure A shows vssadmin being run in a command prompt. Figure A
Click the image to enlarge.
By looking at the configuration of each server, it may give visibility to areas of the system that don't appear in the programs or system tray. VSS components are a different part of Windows and don't have the persistence in other areas like traditional software components. The main thing to look for is any stale components that are not in use anymore, and seek their removal from the local VSS configuration.
What type of housecleaning have you done in the VSS console? Share your tips.
Rick Vanover is a software strategy specialist for Veeam Software, based in Columbus, Ohio. Rick has years of IT experience and focuses on virtualization, Windows-based server administration, and system hardware.