SQL Server 2000 has the capability to do snapshot backups, which
allows backing up a file or a database with minimal impact on
the main system's resources. This is useful not only for making
backups, but also for creating a copy of the production database
for reporting or testing. The snapshot feature needs a third-
party backup application that supports split-mirror or copy-on-
write operations to an appropriate storage device with split
mirroring or copy-on-write features. To use the snapshot, either
for backup or to copy the database, the backup application
typically breaks off one of the mirrors and the data is copied
from it while the main storage system and its mirror continue to
serve the production database. With copy on write, each block is
copied as it is written. In either case, backups kept on disk
can be recreated in a matter of seconds. Because SQL Server
maintains the history of these snapshot databases, the snapshots
can be rolled forward using conventional differential and log
backups to keep t