- Reasons for Backup and Restore
- Backup Problems
- Backup Classifications
- Windows 2000 Backup Utility
- Techniques to Create a Volume Snapshot
- Windows XP and Windows Server 2003 Volume Shadow Copy Service
- Windows-Powered NAS Devices and Snapshots
- Network Data Management Protocol
- Practical Implications
Backup operations have evolved in terms of both user requirements and the technology used to accomplish backups. Usage requirements have dictated that backups be made more frequently, yet without disrupting application access to data. Backup operations evolved from stand-alone backups to backup operations happening across a LAN to backup operations happening in a SAN environment. One problem that backup applications need to solve is backing up open files being accessed by active programs while the backup is being done.
In addition, backup applications have had to deal with a multitude of APIs that are specific to an application version and specific to an operating system version. Yet another trend has been to create the initial backup from disk to disk, via a snapshot operation. Backup to tape is increasingly becoming a secondary backup operation, from the snapshot volume to tape.
The Windows volume shadow copy service provides an efficient way to create snapshots. The architecture provides for all important components, including major applications such as databases and messaging servers to participate in the snapshot creation. Microsoft provides only the infrastructure to create a snapshot. Software vendors may use this infrastructure to build an application that can create and manage multiple snapshots.
Once a snapshot has been created, a backup may be created from the snapshot. Standard protocols such as NDMP may be used to accomplish the backup operation.