Types of backup operations performed using SnapManager

SnapManager supports two types of backup operations:

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

Full database backup

A full database backup contains a full copy of the databases you select. The method that SnapManager uses to create the backup depends on the databases you select. One method involves copying 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 How SnapManager Restore works.

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 system databases
Any user databases that reside on the same LUN as a system database

All other database backups use the online Snapshot backup method.

For SQL Server 2005, if there is no system database on the SQL Server root LUN, SnapManager cannot back up the user databases on that LUN and lists those user databases with the label Invalid next to the LUN drive letter.

Note
A user database cannot reside on a LUN which is also used by SQL root path, SQL data root path, or SQL error log path unless there is a system database on that LUN. 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 2000 or 2005.

Online Snapshot backup method

With this method, SnapManager creates the backup by creating Snapshot copies of the databases. SnapManager uses the online Snapshot method to back up user databases that do not reside on the same LUN as any 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 deselect databases that reside on a different LUN from the database(s) you selected, even if the LUN is on the same storage volume. If the other LUN stores only a single database, you can deselect or reselect that database individually. If the other LUN houses multiple databases, you must deselect 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.

More about volume-wide backups

In a volume-wide backup, all of the databases that reside on a single volume are backed up concurrently.

If the databases reside on the same volume, only one backup Snapshot copy is created.
If the databases reside on multiple volumes, more than one Snapshot copy is created; the databases are grouped by volume and backed up in successive order, one Snapshot copy per volume.
Note
When a Snapshot copy is made of a LUN 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 backup utility.

Transaction log backup

A transaction log backup is a record of the database changes that have occurred since the last transaction log backup. SnapManager supports transaction log backups in order 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:

date_time_databasename.trb

This file is equivalent to the .trn file directly created by SQL Server. The structure of the SnapInfo directory is described in How SnapManager backup data is organized.

Ways to start or schedule a transaction log backup

You can back up a transaction log along with the database or alone.

SnapManager full database backups include the option to also back up the associated transaction logs after the database Snapshot copy backups finish. This is described in Creating a full database backup using SnapManager.
SnapManager also provides the option to back up transaction logs only, independent of the associated databases. This is described in Creating a transaction log backup using SnapManager.

About log shipping and other backup solutions

NetApp recommends that you use SnapManager alone to back up your SQL Server database transaction log files. 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 log shipping is implemented for a particular database, heed the following recommendations:

When using SnapManager Backup, do not back up the transaction logs for that database.
When using SnapManager Restore to restore that database, (1) disable the option to create a transaction log backup before the restore and (2) do not restore the transaction logs.

About Enterprise Manager and Management Studio

SQL Server Enterprise Manager and Management Studio both detect transaction log backups taken by SnapManager for Microsoft SQL Server and restores 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.