Taken in mere seconds, Snapshots make backup administration simple, flexible, and efficient. Moreover, because Snapshots require little time and little storage space, they can be taken several times per day, enabling more frequent full database backups. The storage overhead associated with a Snapshot is based upon the number of blocks that are different between the Snapshot and the active file system. Additionally, if multiple Snapshots exist for a file system, the only Snapshot that actually consumes disk space is the oldest Snapshot. The oldest Snapshot holds the changed data blocks until it is deleted after which the next oldest Snapshot holds the blocks.
Snapshots also provide key advantages in the restoration and recovery of databases.
This paper only focuses on the use of Snapshots and SnapRestore for the backup and restore of SQL Server 7.0 databases stored on a Network Appliance, Inc. filer. While the use of this backup and restore method is both highly efficient and highly reliable, the use of SQL Server 7.0's own backup and restore tools is also a viable choice when storing databases on a Network Appliance, Inc. filer. In order to perform these remote shell operations on the filer, the filer's 'hosts.equiv' file must be appropriately configured. If the hosts.equiv file on the filer is set up correctly, this is a secure operation. SQLServer admin where 'SQLServer' is the name of our SQL Server 7.0 machine and 'admin' is the name of our SQL Server user account.