Everything you want to know about VDS/VSS Hardware Providers

MSys Technologies, one of the leading storage, virtualization, telecommunications, and test automation service provider, has extended its expertise by working with a number of leading storage-domain companies in order to develop and deploy VDS/VSS hardware providers.

Companies in the storage realm, those who manufacture storage solutions such as NAS, SAN, cloud storage products, etc., have been approaching MSys for the past few years to tap into its expertise in successful development in VDS/VSS technology.

What Is VDS/VSS?

Virtual Disk Service (VDS) is a Microsoft technology that extends the existing storage capabilities of Windows operating systems (including Server) at the request of scripts, applications, or end users. In a regular system, VDS assists in several ways:

• Provides an application programming interface (API) for the existing volume- and disk-management features of Windows.
• Under one API, it unifies volume management and RAID-array management.

VDS has three interfaces—one between application layer and the Windows VDS service, and two others running between the service and provider (hardware and software) applications in the data layer. The following diagram illustrates this.

VDS hardware provider, the project that MSys primarily participated in, is a program that implements the methods for managing a storage subsystem, which may be a hardware disk array or adaptor card used for creating logical partitions for enhancing performance, data availability, and recovery. Many RAID manufacturers today support VDS. The capabilities of the hardware provider program depend on the hardware itself.

VSS stands for Volume Shadow Copy Service or Volume Snapshot Service. This is a dynamic Windows service that enables data backup even when an application that creates the data is running. Due to this reason, the backup operation needs to closely coordinate with the application running the backup and the storage hardware and software. VSS service ensures that the data on the disk is fully consistent even if there is a write or read lock.
Here is an illustration for VSS.

VDS and VSS providers play an important role in making any storage server work in a heterogeneous data center environment. These applications make the life of a data center administrator simple, as it helps the storage server to work for a common interface. Backup and restore applications, like Tivoli Storage Manager and Symantec Netbackup, work with heterogeneous storage arrays with the help of their hardware providers.

MSys’s Engagements

With several clients, MSys has helped enhance the VDS and VSS providers to add support for the latest VDS 3.0 specification and newer versions of the controller firmware for one client. In order to build these applications, MSys has used various technologies and languages, such as C++, and COM. The development environments MSys used include Visual Studio 2012 on Microsoft Windows PCs. MSys’s solutions enabled the clients showcase their products alongside some industry-leading backup and restore solutions like Tivoli Storage Manager.
Beyond, these engagements, MSys has also provided VDS/VSS test automation solution for a few clients. For this purpose, MSys’s test automation tool, MTAS, was used.