Archiving SnapManager backups using a Windows backup utility

The following topics discuss archiving SnapManager backups using a Windows backup utility:

About this method

When you use a Windows backup utility to archive your SnapManager backups, you mount the LUNs backed by the backup Snapshot copy you want to archive, and then use NTBackup or another Windows backup utility to copy the archive data to your archive medium. In this case, the NTFS data is backed up, rather than the raw LUNs.

This archive method is represented by the following illustration.

Note
The LUN does not need to be mounted on the SQL Server computer; another network host system that is running SnapDrive can be used for this function.

Components that must be included in the archive

The archive must include the following two components:

The SnapInfo directory as it was backed up directly from the SQL Server computer
The SQL Server data as extracted from the LUN backed by Snapshot copy

Advantages

Using a Windows backup utility to archive SnapManager backups provides these advantages:

Because you are archiving NTFS data, not raw LUNs, you can archive exactly the data that you need, and no more.
The procedures and tools used for this method are probably familiar and available to you.

Disadvantages

The advantages of using a Windows backup utility to archive SnapManager backups must be weighed against these disadvantages:

Because this method relies on mounting a Snapshot copy, you must be careful to avoid scheduling any backups while the archiving is performed. This is because creating a Snapshot copy of a mounted Snapshot copy results in a Snapshot copy that cannot be deleted. For more information about busy Snapshots, see Busy Snapshot error prevents deletion of backup set.
You must make sure that you get both required components from different locations into the same archive. Both components must correspond to the same backup set.

Usage example

The following example illustrates one way to use a Windows backup utility to archive your SnapManager backup sets using a script:

Mount a Snapshot copy of the LUNs that contain the SQL Server databases
Back up the databases using NTBackup.
Dismount the LUNs.
Back up the SnapInfo directory.

Assumptions

This example is based on the following assumptions, which you might need to alter for your environment:

The script is run on the computer running SQL Server and SnapManager.
The drive letter for the SQL Server database is S:.
The Snapshot copy is mounted as drive V:.
The drive letter used for the LUN mount is available when the script is run.

Script

The sample script SampleScript.txt contains the following lines:

REM Mount a LUN backed by the snapshot of the SQL Server database

REM as drive letter V:\.

sdcli snap mount -k s -s %1 -d v

REM Use NTBackup to back up the database files. The path to the

REM databases in your environment might be different. The /N and /D

REM options are included to name the tape and add a description.

ntbackup backup "V:\Program Files\MSSQL\sqldbdata" /N %1 /D %2

REM Dismount the snapshot mounted as drive letter V:\. The -f

REM option causes the drive letter to be forcefully disconnected.

sdcli snap unmount -d v -f

REM Use NTBackup to back up the SnapInfo directory. The media is 
REM appended so as not to overwrite the database backup.

ntbackup backup %3 /T%1 /A

Invoking the script and passing parameters

Use the SnapManager Run Command After Operation feature to invoke the script as follows:

C:\SnapManager Scripts\SampleScript.txt $SqlSnapshot $SnapInfoName 
$SnapInfoPath

The three command-line parameters ($SqlSnapshot, $SnapInfoName, and $SnapInfoPath) correspond with the script variables (%1, %2, and %3), as summarized in the following table.

Variable		Sample value passed to the script
Script	Command- line	Sample value passed to the script
%1	$SqlSnapshot	`sqlsnap__winsrvr2__recent`
%2	$SnapInfoName	`WINSRVR2__recent`
%3	$SnapInfoPath	`I:\SMSQL_SnapInfo\SQL__WINSRVR2\DB__Northwind`

For more information about the Run Command After Operation feature, see Using the Run Command After Operation feature.