Creating a Snapshot

Prerequisites

• The HyperSnap license is valid.
• No other features configured for the source LUN conflict with HyperSnap.
• If the usable capacity of the storage pool where the source LUN resides is 0, snapshots cannot be created for the LUN.

Context

• On DeviceManager, the snapshots of VVol LUNs can be viewed only.
• The maximum number of snapshots supported by each source LUN varies with product models. For details, see "Software Specifications" in the Product Description specific to each version.

Procedure

1. Log in to DeviceManager.
2. Choose Data Protection > Snapshot > LUN.
3. In the function pane, click Create.

   The Create Snapshot dialog box is displayed.

4. Create a snapshot and set parameters for it.
   1. In Create Snapshot, select the source LUN for which you want to create a snapshot.
   2. Set parameters for the snapshot.

      Table 2-2 describes the related parameters.

      Table 2-2 Snapshot parameters

      Parameter	Description	Example Value
      Snapshot Name	Name of a snapshot. The name must be unique. The name contains letters, digits, underscores (_), periods (.), and hyphens (-). The name contains 1 to 31 characters.	Snapshot001
      Activate Now	Determines whether to activate a snapshot. Yes: indicates that a data copy of the source LUN is generated immediately after the snapshot is created. Running Status of the snapshot is Activated. No: indicates that the snapshot is not activated after being created. Running Status of the snapshot is Unactivated and you can manually activate the snapshot.	Yes NOTE: The default value is also Yes.
      Snapshot Description (optional)	Description of a snapshot. The description contains 0 to 255 characters.	-

   • By default, the system activates a snapshot immediately after it is created. You can click Cancel Activation to cancel the batch activation of selected snapshots. You can click Activate Now to activate selected snapshots in batches. After clicking Activate Now, the snapshots will be created and activated in the background one by one.
   • In Create Snapshot, select the LUNs for which you want to create snapshots and select Consistently Activate. After this operation, the snapshots will be created in batches in the background, and then snapshots that are created successfully will be activated in batches.
   3. Click OK.

      The Execution Result dialog box is displayed, indicating that the operation succeeded.

5. Click Close.

Follow-up Procedure

• In addition to manually creating snapshots, you can use BCManager eReplication to configure periodic snapshots for snapshots to be generated as scheduled.
• The snapshot generated can be mapped, like a common LUN, to a host for use. See details in Basic Storage Service Configuration Guide for Block.
• Because of the LUN identification mechanism used by hosts' operating systems and volume managers, do not map both the source and snapshot LUNs to the same host. For example, in Oracle ASM, hosts distinguish between LUNs by ASM disk headers and may wrongly identify the source and snapshot LUNs as the same LUN, causing data corruption on the two LUNs.
• You can delete the snapshot LUNs that have been mapped to hosts and delete host mappings. For details about the operations, see section "Deleting a Mapping View" in the Basic Storage Service Configuration Guide for Block.