Using NDMP or dump to archive SnapManager backups

You can use NDMP or the storage system's dump command to archive the LUNs containing the Exchange 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

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

This archive method is represented by the following diagram:

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 the following advantages:

Because this method does not rely on mounting a Snapshot copy, it does not risk the creation of busy Snapshot copies.
Because this method archives the entire raw LUN, restoring is simply a matter of replacing the LUNs.
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 weighted against the following disadvantages:

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

Path name to use when archiving using NDMP or dump

When using NDMP or dump to archive your SnapManager backups, specify the database LUN using its absolute path name

/vol/volume_name/.snapshot/snapshot_name/LUN_name

where the three variables represent the following text strings:

Variable	Description
volume_name	Name of the volume containing the data to be archived
snapshot_name	Name of the Snapshot copy containing the LUNs to be archived For more information about SnapManager Snapshot copy naming conventions, see SnapManager Snapshot copy naming conventions.
LUN_name	Name of the LUN containing the data to be archived

Variable

Description

volume_name

Name of the volume containing the data to be archived

snapshot_name

Name of the Snapshot copy containing the LUNs to be archived

For more information about SnapManager Snapshot copy naming conventions, see SnapManager Snapshot copy naming conventions.

LUN_name

Name of the LUN containing the data to be archived

For example, the absolute path name of the LUN exch1db.lun in the Snapshot copy exchsnap__SRVR3_01-20-2006_12.05.58_Daily on the volume ExchVoln is:

/vol/ExchVol/.snapshot/exchsnap__SRVR3_01-20-2006_12.05.58__Daily/exch1db.lun

Usage example

Suppose you want to use a script to archive your SnapManager backups to tape in the following environment:

The script is run on the computer running Exchange and SnapManager.
The name of the storage system is Filer1.
The name of the LUN containing the Exchange databases is exch1db.lun.
The name of the LUN containing the Exchange transaction logs and the SnapInfo directory is exch1logs.lun.
The name of the volume containing the Exchange databases is Exchvol.

Example script

The following script uses the storage system dump command to dump the database, transaction logs, and SnapInfo LUNs to tape. This script relies on rsh functioning on the Exchange server using the SnapManager user account.

REM Back up the LUN containing the Exchange database.

REM For this example, a level 0 backup is performed

REM to the tape device named nrst0a.

rsh Filer1 dump 0f nrst0a /vol/ExchVol/.snapshot/%1/exch1db.lun

REM Before appending the next backup to the tape, 

REM reposition to the end of the tape so the next

REM write will not overwrite the existing data.

rsh Filer1 mt -f nrst0a eom

REM Back up the LUN containing the Exchange 

REM transaction log files and the SnapManager SnapInfo

REM directory.

rsh Filer1 dump 0f nrst0a /vol/ExchVol/.snapshot/%2/exch1logs.lun

Invoking the script and passing parameters

To invoke this script using the SnapManager Run Command After Operation feature, use the following command:

C:\SnapManager Scripts\scriptname.txt $ExchSnapshot $InfoSnapshot

The command-line parameters %1 and %2 might provide values similar to the following, respectively:

exchsnap__SRVR3_01-20-2006_12.05.58__Daily
eloginfo__SRVR3_01-20-2006_12.05.58__Daily

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

Invoking the script without using command-line parameters

If you prefer not to use the Run Command After Operation feature and you are not using the unique name option for your backups, you can hardcode the Snapshot copy names into the script.

For example, the dump command for the database might look like this, for an Exchange server named SRVR3:

rsh Filer1 dump 0f nrst0a 
/vol/Exch/.snapshot/exchsnap__SRVR3__recent__Daily/exch1logs.lun