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NetBackup™ Web UI Microsoft SQL Server Administrator's Guide

Last Published: 2023-03-31

Product(s): NetBackup & Alta Data Protection (10.2)

Performance tuning and configuration options

Table: Performance tuning and configuration options describes the tuning and configuration options that are available that are available in protection plans. Some options cannot be changed when you edit an existing plan or when you subscribe an asset to the plan.

Note:

Filegroup backups are only available for policies and not for protection plans.

Table: Performance tuning and configuration options

Field	Description
Backup stripes	This option divides the backup operation into multiple concurrent streams. A stream corresponds to a job in the activity monitor. For example, if the value is 3, each database is backed up using three jobs. This configuration applies in any situation in which SQL Server dumps data faster than your tape drive is capable of writing. The default value for this option is 1. Range is 1 - 32.
Client buffers per stripe	(Stream-based backups only) This option affects buffer space availability. NetBackup uses this parameter to decide how many buffers to allocate for reading or writing each data stream during a backup operation. By allocating a greater number of buffers, you can affect how quickly NetBackup can send data to the NetBackup primary server. The default value for this option is 2, which allows double buffering. You may get slightly better performance by increasing this value to a higher value. Range is 1 - 32.
Maximum transfer size	(Stream-based backups only) This option is the buffer size used by SQL Server for reading and writing backup images. Generally, you can get better SQL Server performance by using a larger value. This option can be set for each backup operation. Calculated as 64 KB * 2^MAX_TRANSFER_SIZE. It ranges in size from 64 KB to 4 MB. The default is 4 MB.
Backup block size	This option applies to stream-based backups only. Sets the incremental size that SQL Server uses for reading and writing backup images and can be set for each backup operation. Calculated as 512 bytes * 2^BLOCK_SIZE. The value for this option ranges from 0.5 KB to 64 KB. The default is 64 KB.
Parallel backup operations	This option is the number of backup operations to start simultaneously, per database instance. Range is 1 - 32. The default is 1.
VDI timeout (seconds)	(Databases only) Determines the time-out interval for SQL Server Virtual Device Interface. The selected interval is applied to backups and restores of databases and of transaction logs. The default value for backups is 300. The default value for restore jobs is 600. Range is 300 - 2147483647.
Use Microsoft SQL Server compression	Enable this option to use SQL Server to compress the backup image. If you enable SQL Server compression, do not enable NetBackup compression. SQL Server compression is not supported for snapshot backups.
Skip unavailable (offline, restoring, etc.) databases	NetBackup skips any database with a status that prevents NetBackup from successfully backing up the database. These statuses include offline, restoring, recovering, and emergency mode, etc. NetBackup skips the backup of the unavailable database, but continues with the backup of the other databases that are subscribed to the protection plan. The backup completes with a status 0 and the job details indicate that the database was skipped.
Create copy-only backup	(Databases only) This option allows SQL Server to create an out-of-band backup so that it does not interfere with the normal backup sequence. See Using copy-only snapshot backups to affect how differentials are based.
Perform Microsoft SQL Server checksum	Choose one of the following options for SQL Server backup checksums: None. Disables the backup checksums. To verify the checksums before the backup, choose one of the following options. Note that these options impose a performance penalty on a backup or restore operation. Continue on error. If the backup encounters a verification error, the backup continues. Fail on error. If the backup encounters a verification error, the backup stops.
Convert incremental backup to full backup	(Databases only) If no previous full backup exists for the database, then NetBackup converts a differential backup to a full backup. The agent determines if a full backup exists for each database. If no previous full backup exists, a differential backup is converted to a full as follows: If you select a database for a differential backup, the backup is converted to a full database backup. (For policies) If the Skip read-only file groups option is selected the backup is converted to a full read/write filegroup backup. (For policies) If you select a filegroup for a differential backup, NetBackup does the following: If the filegroup is the default database filegroup, NetBackup converts the backup to a full filegroup backup. If the filegroup is a secondary filegroup and a backup of the primary filegroup does not exist, NetBackup converts the backup to a partial full database backup. This backup contains the selected filegroup and default filegroup. If the filegroup is a secondary filegroup and a backup of the primary filegroup does exist, NetBackup converts the backup to a full filegroup backup of the selected filegroup. For snapshot backup policies, a Full schedule must exist to successfully convert differential backups to full backups. Note: NetBackup only converts a differential backup if a full backup was never performed on the database. If a full backup does not exist in the NetBackup catalog but SQL Server detects an existing full LSN, NetBackup performs a differential backup and not a full. In this situation, you can restore the full backup with native tools and any differentials with the NetBackup MS SQL Client. Or, if you expired the backup in NetBackup, you can import the full backups into the NetBackup catalog. Then you can restore both the full and the differential backups with the NetBackup MS SQL Client.
Convert transaction log backup to full backup	(Transaction logs only) If no previous full backup exists for the database, then NetBackup converts a transaction backup to a full backup. This option also detects if a full recovery database was switched to the simple recovery model and back to the full recovery model. In this scenario, the log chain is broken and SQL Server requires a differential backup before a subsequent log backup can be created. If NetBackup detects this situation, the backup is converted to a differential database backup. Note: NetBackup only converts a transaction log backup if a full backup was never performed on the database. If a full backup does not exist in the NetBackup catalog but SQL Server detects an existing full LSN, NetBackup performs a transaction log backup and not a full. In this situation, you can restore the full backup with native tools and any differentials and log backups with the NetBackup MS SQL Client. Or, if the backup is expired, you can import the full backups into the NetBackup catalog. Then you can restore the full, differential, and log backups with the NetBackup MS SQL Client.
Availability database backup preference	This option determines where backups of availability groups occur. Select a setting for databases in the Database options tab. Select a setting for transaction logs on the Transaction logs tab. Disabled (for policies, the equivalent setting is None) Performs the backup on the specified instance. Use this option when you intend to protect individual availability databases. Protect primary replica Backups always occur on the primary replica. This option applies to availability replicas and to instances that have both standard databases and availability databases. Protect preferred replica Honors your SQL Server backup preferences. These preferences include the preferred replica, backup priority, and excluded replicas. Note that NetBackup initiates a backup job on each replica. The backup is skipped on any replica that isn't the intended backup source. This option applies to availability replicas and to instances that have both standard databases and availability databases, Skip availability databases Skips any availability databases on the instance. Use this option when you intend to protect any instances that contain both standalone databases and availability databases and only want to protect the standalone databases. Note: Do not select this option if you intend to protect availability groups. Backup preference for individual availability databases Note the following behavior when you select a protection plan to protect individual availability databases. If the preference for Databases is set to Skip availability databases, scheduled backups cannot succeed. Databases must have the setting None, Protect preferred replica, or Protect primary replica. When a user selects Backup now to back up an availability database, the backup is performed on the selected node. The image is cataloged under the cluster name.
Truncate logs after backup	(Transaction logs only) This option backs up the active part of the transaction log and then marks it inactive or empty. This option is enabled by default.