Using NDMP or dump to archive SnapManager backups

About this method

When you use NDMP or dump to archive your SnapManager backups, you use NDMP or the filer'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 filer data to tape, see the System Administration Data Protection Guide for your version of Data ONTAP.

Advantages and disadvantages of this method

Using NDMP or dump to archive SnapManager backups provides the following advantages and disadvantages:

Advantages

Because this method does not rely on mounting a snapshot, 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.
If your archive procedure does not send the data over the network, this method can be significantly faster than other methods.

Disadvantages:

Because you are archiving raw LUNs, the entire LUN containing the Exchange 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.

Path name to use when archiving using NDMP or dump

You use the following absolute path name when using the NDMP or dump archive method:

/vol/volume_name/.snapshot/snapshot_name/LUN_name

volume_name is the name of the volume containing the data to be archived.
snapshot_name is the name of the snapshot containing the LUNs you want to archive.
For more information about SnapManager snapshot naming conventions, see SnapManager snapshot naming conventions.
LUN_name is the name of the LUN containing the data to be archived.

Usage example

The following script uses the filer's 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.

This script uses the following assumptions, which you might need to alter for your environment:

The script is run on the computer running Exchange and SnapManager.
The name of the filer 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.

Script

REM Back up the LUN containing the Exchange

REM database. For this example, a level 0 backup is

REM performed 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

Command line parameters

This script can be invoked using the SnapManager Run Command After Operation feature with the following command:

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

These command-line parameters provide values to the script similar to these examples:

%1: exchsnap__SRVR3_01-20-2004_12.05.58__Daily
%2: eloginfo__SRVR3_01-20-2004_12.05.58__Daily

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

Script invocation 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 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