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Types of backup operations performed using SnapManager

Types of SnapManager backup

SnapManager supports two types of backup operations:

A transaction log backup can be included in a full database backup, or it can be created as a log-only backup set.

Copy only backup (database and transaction log) can be selected while configuring backup operation.

Full database backup

A full database backup contains a full copy of the databases that you select. The method that SnapManager uses to create the backup depends on the databases that you select. One method involves streaming out the content of the databases individually, while the other method consists of creating Snapshot copies of the databases. The method that SnapManager uses to create a particular backup set has implications for how SnapManager restores databases from that backup set. For more information, see Understanding SnapManager Restore.

Stream-based backup method With this method, SnapManager creates the full database backup by streaming out the contents of the databases individually. SnapManager uses the stream-based method to back up the following:

All other database backups use the online Snapshot copy backup method.

Note: If there is a system database on the LUN or VMDK that hosts the SQL Server, a user database should not reside on that LUN or VMDK. This restriction is enforced by the Configuration wizard.

Full database stream-based backup files are .fbk files named using the convention date_time_databasename: for example, 050802_0330_xxx.fbk. This file is equivalent to the .bak file directly created by SQL Server.

Online Snapshot copies backup method With this method, SnapManager creates the backup by creating Snapshot copies of the databases. SnapManager uses the online Snapshot method to backup all user databases that reside on SMB shares and the user databases that do not reside on the same LUN or VMDK as system databases. All other database backups use the stream-based backup method.

When you select a database for a full database backup, SnapManager automatically selects all other databases that reside on the same storage system volume. You can clear databases that reside on a different LUN, SMB share, or VMDK from the databases you selected, even if the LUN, SMB share, or VMDK is on the same storage volume. If the other LUN, SMB share, or VMDK stores only a single database, you can clear or reselect that database individually. If the other LUN, SMB share, or VMDK houses multiple databases, you must clear or reselect those databases as a group.

For a description of the naming convention used by full database online Snapshot backup sets, see "SnapManager backup set names" in How SnapManager backup data is organized.

More about volume-wide backups In a volume-wide backup, all the databases that reside on a single volume are backed up concurrently using Snapshot copies. If the maximum number of concurrent backup databases is 35, then the total number of Snapshot copies created equals the number of databases divided by 35.

Note: When a Snapshot copy is made for a SnapManager backup, the entire storage system volume is captured in that Snapshot copy. However, that backup is valid only for the SQL host server for which the backup was created. If data from other SQL host servers resides on the same volume, that data is not restorable from the Snapshot copy.

About Enterprise Manager and Management Studio Although SnapManager Snapshot copy full database backup files are viewable from the Enterprise Manager or Management Studio of your SQL Server, you cannot perform any operations on them using the SQL Server Enterprise Manager or Management Studio.

Transaction log backup

A transaction log backup is a record of the committed database changes that have occurred since the last transaction log backup that was truncated after the backup completed. SnapManager supports transaction log backups to provide a more granular level of database backup and to recover the transactions committed since the most recent full backup.

File name and location SnapManager creates a backup of a transaction log by copying transaction log data to a file in the SnapInfo directory. Transaction log backup files are named using the following convention:

This file is equivalent to the .trn file directly created by SQL Server Management Studio. The structure of the SnapInfo directory is described in Ways to manage the number of backup sets kept online.

Ways to start or schedule a transaction log backup You can backup a transaction log along with the database or alone.

About log shipping and other backup solutions It is best to use SnapManager only, to back up your SQL Server database transaction log files. Snap Manager does support log shipping; therefore, if you decide to use a different backup solution, use it alone as well; do not attempt to restore from backup files that were created using different backup solutions. If you use log shipping, you cannot backup the transaction logs for that database.

If log shipping is implemented for a particular database, remember the following recommendations:

About Enterprise Manager and Management Studio SQL Server Enterprise Manager and Management Studio both detect transaction log backups made by SnapManager for Microsoft SQL Server, and can be used to restore the database to a further point in time by applying transaction log backups in sequence. However, neither Enterprise Manager nor Management Studio can restore full database backups of Snapshot copies made by SnapManager for Microsoft SQL Server.