Back up with SQL Server Virtual Device Interface (VDI)

Microsoft's Virtual Device Interface (VDI) is integral to all third-party SQL Server backup solutions, whether hardware or software. The VDI provides third-party vendors access to a collection of high-performance backup-and-restore mechanisms. By writing to the VDI, developers can substitute a virtual device for a server's local disk file or tape. VDIs enable third-party software to control SQL Server backup and restore, which allows vendors to create a seamless interface between their own high-performance technologies and the SQL Server. Third-party applications can use the VDI interface to perform snapshot as well as standard SQL Server backup and restore. However, VDI under the SQL Server 7.0 does not permit true third-party integration. It supports only standard SQL Server backup and restore. SQL Server, through its support for snapshot backups, treats the third-party solutions as true backups. In this case, the backup of volumes and databases must be performed in the traditional manner. The ability to back up and restore data in a reliable and timely manner requires the SQL Server VDI (Virtual Backup Device API). Most third-party independent software vendors use the VDI application programming interface to integrate SQL Server into their products. The advantages and disadvantages of VDI are as follows: Advantages This API is engineered to provide maximum reliability and performance to support the full range of SQL Server backup and restore functionality. This API is used by most third-party vendors to perform backup/recovery operations. The VDI provides parallel high-speed data transfer between the SQL Server and the snapshot provider with minimal overhead. Disadvantages Only utilities that interact with the SQL Server through the VDI can issue the backup and restore command snapshot option. Users cannot issue the snapshot option directly. SQL Server supports only the backups and restorations saved in the snapshot format. It does not support differential and transaction log backups saved as snapshots. Backup/restore of the SQL Server database is possible using the SQL Server Enterprise Manager or VDI. However, an integrated solution to back up both the SQL database and volumes is not possible using these approaches. Backup/recovery of Teamcenter volumes must be performed using the traditional copy and paste method. VDI combined with the third-party integrations can effectively back up and restore Teamcenter metadata and files that require minimal downtime and require SQL Server 2000/2005 to be in hot backup mode. This combination enables you to achieve greater flexibility by ensuring 24 X 7 availability.