Parallel Backup and Restore

Parallel backup and restore operations improve the capability of Microsoft® SQL Server™ to manage very large databases. The BACKUP and RESTORE statements use parallel I/O in a number of ways:

• If a database has files on several disk devices, BACKUP uses one thread per disk device to read the extents from the database.
• If a backup set is stored on multiple backup devices, both the BACKUP and RESTORE statements use one thread per backup device.
• If a database is defined with files on several disk drives, and RESTORE has to create the database, RESTORE uses one thread per disk device while it is initializing the database.