Configuration Configuring multi-stream operations
Configuring multi-stream operations
NetBackup supports multi-striped and multiplexed backups of SQL Server. Backup streams can each be written to separate storage units or multiplexed to a single storage unit.
Configuring multi-striped backups
SQL Server supports backups of databases through multiple data streams, which are called stripes. NetBackup stores each stripe as a separate image. The purpose of this feature is to speed up the rate of data transmission by using multiple tape devices in case the tape device is a bottleneck.
Generally Symantec does not recommend that you enable multiplexing for a schedule that is used for backing up multiple stripes.
Backup images can be written to more tapes than available drives. If this situation, in the batch file for the restore operation, indicate the number of drives that are available. See “Restoring multi-streamed backups” on page 116.
To configure a multi-striped backup policy
In your Application Backup policy, set Media multiplexing to 1 in the schedule you will use for striped backups or restores.
This disables multiplexing for this schedule. This will make all streams simultaneously available so restore operations will be successful.
Ensure that the storage unit has as many drives as you will have stripes.
Configure schedules for backups and restores so that enough drives are available at the time you will be performing striped backups or restores.
In the Backup Microsoft SQL Server Objects dialog box, select a Stripes setting greater than 1.
Configuring multiplexed backups
NetBackup provides a multiplexing feature that allows you to interleave multiple backups to the same tape. Multiplexing is useful if you have many simultaneous backups using the same tape drive. However, it can interfere with SQL Server recovery due to how SQL Server requests streams during restore. If you do use multiplexing when doing multi-streamed backups, “Restoring multi-streamed backups” on page 116.
To configure multiplexed backups
In the schedule for your Application Backup policy, set Media multiplexing to the number of backup stripes that you plan to use.