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How to create iSCSI volume Snapshot on TeraStation 6000


Snapshot is a function that creates a virtual copy of the data currently stored in a shared folder or iSCSI volume on the TeraStation. Once a snapshot has been created and saved, files and folders that are subsequently modified or deleted can be restored from the point at which the snapshot was created.
The created snapshots will be saved on the TeraStation. As with any file, if a drive or array malfunctions, all saved snapshots on that drive or array will be unrecoverable along with the data.

Application for iSCSI Volume Snapshots
To create an iSCSI volume snapshot in the environment where the iSCSI volumes on the TeraStation are connected using a virtual machine, we recommend using the Buffalo-offered Windows Server application “Snapshot Agent for TeraStation”, available from the Buffalo website.
The application can create both application-consistent and crash-consistent snapshots. An application-consistent snapshot contains all current data in memory and all I/O operations. Restoring from an application-consistent snapshot reverts the virtual machine to the exact same state as when the snapshot was created. A crash-consistent snapshot, on the other hand, creates a snapshot of all the current files but not ongoing processes. Restoring from a crash-consistent snapshot only recovers saved data.

For host server OS that is not supported by the Snapshot agent application, it is recommended to properly unmount the TeraStation iSCSI volume from server before taking iSCSI snapshot for data consistency.

 

iSCSI Volume Snapshot
1.    From the Storage  tab, Click the settings icon to the right of “iSCSI”.

 

2.    Select the checkbox for the target iSCSI volume and click Show Snapshot List.
 


3.    Click Create.


4.    Select or clear the “Lock snapshot” checkbox to determine whether the created snapshot will be locked or unlocked. A locked snapshot will not be deleted by auto-archiving.
Enter a short description if desired, then click OK.

5.    The snapshot taking will start to progress. Click OK.

6.    After the snapshot progress finishes, the snapshot will be created on this iSCSI volume.

Note: Up to 1024 snapshots can be created for an iSCSI volume. We recommend keeping no more than 65,536 snapshots total on a TeraStation. If you have created more than 65,536 snapshots, it may result in unexpected system behavior and slowdown.

 

Schedule Snapshots
The TeraStation allows you to not only create a snapshot manually, but also schedule automatic snapshots and auto-archive them to save TeraStation capacity.
If you want to create a snapshot for the purpose of regular backups, follow the procedure below.

1.    At the Snapshot list window of the iSCSI volume which you want to schedule snapshot, click Advanced Settings at the lower-left corner of the window.

2.    At the Schedule tab, click Enable to enable schedule snapshot.
 
3.    Select the day of the week and time for when to automatically create a snapshot. Then Click OK.


Snapshot Archiving
If you regularly create snapshots, it will use up capacity on the TeraStation. Snapshot archive settings will allow you to save capacity on created snapshots by automatically deleting older snapshots. You can set either a version-based or a timeline-based rule to delete snapshots.
Note: The locked snapshots will be kept even if archive settings are in effect.
1.    At the Snapshot list window of the iSCSI volume you want to schedule snapshot, click Advanced Settings at the lower-left corner of the window.

2.    At the Auto Archive  tab, select the rule to keep the snapshots.


Restoring iSCSI volume Snapshots
Note: When restoring snapshots, the iSCSI service will restart so iSCSI volumes will become unable to connect temporarily. If you have saved the virtual machine to the iSCSI volume, shut down the virtual machine before restoring.
Note1: It is recommended to properly unmount the restoring TeraStation iSCSI volume from the server before restoring iSCSI snapshot for server stability.

1.    At the Snapshot list window of the iSCSI volume you want to restore snapshot,
select the checkbox for the target snapshot and then click Restore.

 

2.    A new snapshot of the current state will be created before restoring the snapshot.
Select or clear the “Lock snapshot” checkbox to determine whether the created snapshot will be locked or unlocked. A locked snapshot will not be deleted by auto-archiving.
Enter a short description if desired, then click OK.

Click OK when completed.

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