Summary
DPX can be used to seed a SnapMirror relationship between two NetApp storage servers. The benefits to using DPX are the ability to backup and retain you data set, use multiple tapes in the backup/restore process, and use multiple forms of media including real tapes, VTL, or DISKDIRECTORY disk-based media devices.
Resolution
DPX Backup and Restore:
- Your NetApp FAS device must be scanned into the DPX Enterprise with the Backup Type field set to smtape. To check this, go into Configure > Enterprise, select the source NetApp server, and review the Backup Type field. If this field indicates dump, change it for this procedure. Use the drop-down menu to select smtape, and then click Apply at the bottom of the Edit Node window.
It is very important to take care when changing the Configure > Enterprise field. The Backup Type affects all NDMP backups for this device. Do not try to run NetApp NDMP backups of different types at the same time; it may not produce the intended result. If you are changing the Backup Type to smtape for NetApp device seeding, ensure that this done at a time when other NDMP backups for this device are not running, and remember to change the value back to dump, if necessary. - Create a new NDMP backup job. Select the volume on the source NetApp server and the desired destination (tape drive, tape library, DISKDIRECTORY device cluster). You must select the whole volume for backup; smtape backup is not valid for subdirectories and qtrees that exist within volumes.
- Open Set Source Options on the job window. Add the following entry to the Additional NDMP Environment field:
SMTAPE_DELETE_SNAPSHOT=N
Click OK, save your job, and run the backup job. - Verify that the source NetApp server has retained the smtape snapshot. This is required for the SnapMirror synchronization. Using FilerView, System Manager, or DPX NDMP backup browse, drill into the volume you backed up .snapshot folder, and verify that you see a new snapshot similar to the following:
snapshot_for_smtape.a73564ac-fc33-11e0-b928-00a09826dcc8.0 - Transport your media to the remote site.
- Create a new volume on the destination NetApp device. This volume must be the same size or larger for the SMTAPE restore process to succeed. It does not matter if the volume is set to reserve space or not. Once the volume is created, restrict this volume.
- Setup a DPX restore job. The system must be able to access the backup media volume from a tape device, tape library, or device cluster which is local to the destination NetApp device. No other special options are required. Run the restore process to the destination NetApp device and the restricted volume created for SnapMirror synchronization. When the restore is completed, check the volume. Its status should change from restricted to something similar to online, snapmirrored, read-only.
NetApp Preparation:
At this point, the DPX backup and restore process is complete. The following procedures are standard NetApp procedures used to manipulate volumes and set up SnapMirror relationships. This can be accomplished via command line or with a graphical utility such as FilerView or System Manager.
It is highly recommended that both NetApp devices have the same Data ONTAP version and similar licensing. Although data can be replicated between different Data ONTAP versions and licensed features, the destination side may not be able to make use of the data when it is need. Consult NetApp support or engineering for additional details.
SnapMirror is initiated from the destination side. Both NetApp devices need to know about one another; this is usually configured either via DNS or via the device's local hosts file. Both devices must be able to communicate to one another and have the necessary licenses installed for SnapMirror.
Assuming that the necessary SnapMirror prerequisites are in place (consult NetApp documentation or technical support), the following commands can be used to break the relationship to the smtape backup and resynchronize it back to the original server.
NetApp SnapMirror Synchronization:
- Run snapmirror status. Output similar to the following displays:
Snapmirror is on
This is followed by the known SnapMirror relationship. Look for the volume used for the DPX restore and the corresponding snapshot_for_smtape relationship. By way of example, something similar to the following displays:
Source snapshot_for_smtape.a73564ac-fc33-11e0-b928-00a09826dcc8.0
Destination fas2040c-1:TESTvol_sm
State Snapmirrored - Break the smtape relationship. Use snapmirror break <volname>. Following the example above, this is:
snapmirror break TESTvol_sm
Assuming the operation is successful, output similar to the following displays:
snapmirror break: Destination TESTvol_sm is now writable. - Resync the destination SnapMirror with its source. This is done with the snapmirror resync command. This command requires the name and volume of the original source, and the name and volume of the destination. An example of this is:
snapmirror resync -S fas2040b:TESTvol fas2040c-1:TESTvol_sm
This command confirms "Are you sure you want to resync the volume?". Enter y and press Enter to continue. On success, output similar to the following displays:
The resync base snapshot will be: snapshot_for_smtape.a73564ac-fc33-11e0-b928-00a09826dcc8.0
Are you sure you want to resync the volume? Y
Wed Oct 19 18:40:57 EST [snapmirror.dst.resync.info:notice]: SnapMirror resync of TESTvol_sm to fas2040b:TESTvol is using snapshot_for_smtape.a73564ac-fc33-11e0-b928-00a09826dcc8.0 as the base snapshot.
Volume TESTvol_sm will be briefly unavailable before coming back online.
Wed Oct 19 18:40:58 EST [wafl.snaprestore.revert:notice]: Reverting volume TESTvol_sm to a previous snapshot.
Revert to resync base snapshot was successful.
Wed Oct 19 18:40:59 EST [replication.dst.resync.success:notice]: SnapMirror resync of TESTvol_sm to fas2040b:TESTvol was successful
Transfer started.
Monitor progress with 'snapmirror status' or the snapmirror log.