Archiving SnapManager backups using NDMP or dump

You can use NDMP or the storage system's dump command to archive the LUNs containing the SQL Server data and the SnapInfo directory directly from the storage system to the archive medium. NDMP and the dump command are the most efficient methods for creating archives of the LUN drive files. See the following topics for more information:

• About this method
• Guidelines for archiving using NDMP or the dump command
• Procedure for archiving using NDMP or the dump command

About this method  

When you use NDMP or the storage system's dump command to archive your SnapManager backups, you archive each LUN that contains data for that backup set. This method enables you to archive your SnapManager backup sets without involving SQL Server at all. Snapshot copies are taken of the LUNs, then copied to the archive medium and deleted.

This archive method is represented by the following illustration.

For more information about backing up storage system data to tape, see the System Administration Data Protection Guide for your version of Data ONTAP.

Advantages

Using NDMP or dump to archive SnapManager backups provides these advantages:

• Because this method does not rely on mounting a Snapshot copy, it does not risk the creation of busy Snapshots.
• Because this method archives the entire raw LUN, restoring is simply a matter of replacing the LUNs.

  Note
  In this case, you need to run SnapManager in "restore from archive mode" to perform the restore operation. This is described in Recovering SQL Server databases using archives.

• If your archive procedure does not send the data over the network, this method can be significantly faster than other methods.

Disadvantages

The advantages of using NDMP or dump to archive SnapManager backups must be weighed against these disadvantages:

• Because you are archiving raw LUNs, the entire LUN containing the SQL Server data is archived, so you archive more data than you need.

  Note
  If archiving extra data is undesirable, you can use NTBackup or another Windows backup utility to back up the corresponding SnapInfo directory. This must be coordinated so that the two pieces of the archive are kept together for later retrieval.

• If you archive the SnapInfo directory separately, you must ensure that you get both required components from different locations into the same archive.

Guidelines for archiving using NDMP or the dump command  

When archiving using NDMP or dump, follow these guidelines:

• When using the NDMP- or dump-based archive method, back up the database LUN at the following location:

  /vol/VolumeName/.snapshot/sqlsnap__HostName__recent/FileName

  sqlsnap__HostName__recent is the name of the Snapshot copy you want to archive.

• Whether the LUN object was archived using the dump command on the storage system or through NDMP, backing up the SnapInfo directory can be a separate process. Although the entire LUN where the SnapInfo directory resides can be backed up as a whole, you back up more than you need to; therefore, this method is not very efficient. Backing up the LUN object that contains the SnapInfo directory (this filename is different from the filename for the LUN that contains the databases) can be done in the same way as backing up the LUN objects for the database disks, as described in the previous two points.

  It is more efficient to back up only that which you need, directly from the SQL Server.

Procedure for archiving using NDMP or the dump command  

To back up directly from the SQL Server, complete the following steps.

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Last updated: 01-Sep-2006 07:41:22