Creating a HyperMetro CG

Context

When you create a HyperMetro CG using a LUN group, the system first creates a PG for this LUN group. If you want to create a HyperMetro CG using a PG, choose Data Protection > Protection Entities > Protection Groups > Protection Groups and manually create a PG. Then create a HyperMetro CG for the PG.

Prerequisites

• The local and remote devices work normally and correctly communicate with each other.
• The local and remote devices support HyperMetro.
• A storage pool has been created on the remote storage system.
• Remote LUNs (if created) have not been mapped to any host.
• You cannot create a HyperMetro CG for a LUN group if a remote replication CG has been created for this LUN group and the HyperMetro CG you want to create uses the same remote device as this remote replication CG.

Precautions

• If Pair Creation is set to Automatic, the system automatically creates remote LUNs and a remote LUN group on the remote storage system, and adds them to HyperMetro pairs and a CG. Ensure that no HyperMetro pair has been created for the LUNs in the LUN group. If remote LUNs or HyperMetro pairs already exist, create the CG manually to prevent configuration conflicts.
• If Pair Creation is set to Manual, you must manually select a LUN group on the remote storage system, which must contain the same number and capacities of LUNs as the local LUN group, and then manually match the LUNs. Ensure that the remote LUN group and its LUNs have not been mapped. If the LUN group or any LUN has been mapped, delete the mapping first to prevent configuration conflicts.

Procedure

1. Choose Services > Block Service > LUN Groups.
2. Select the desired LUN group, click Protect, and select Create HyperMetro. The Create HyperMetro CG page is displayed.

   On the Create HyperMetro CG page, you can query the name of the protection group that is automatically created by the system.

3. Select a HyperMetro domain in which you want to create a HyperMetro CG.
4. Set Pair Creation to Automatic.

   If you set Pair Creation to Manual, you must manually create remote LUNs and LUN group and create a HyperMetro CG for the local and remote LUNs.

5. Select the target storage pool for creating remote resources of HyperMetro.
6. (Optional) Select Advanced in the upper right corner and set the advanced parameters.

   By default, Speed is Medium, Recovery Policy is Automatic, and Initial Sync is Automatic.

   Table 10-6 describes the parameters.

   Table 10-6 HyperMetro CG advanced properties

   Parameter	Description
   Speed	Data synchronization speed of the HyperMetro CG. Possible values are as follows: Low: 0 to 5 MB/s. At this setting, data synchronization takes a long period. This value is used when the service load is heavy. Medium: 10 MB/s to 20 MB/s. At this setting, data synchronization takes a relatively short period. This value is used when the service load is relatively heavy. High: 20 MB/s to 70 MB/s. At this setting, data synchronization takes a short period. This value is used when the service load is relatively light. Highest: Above 100 MB/s. At this setting, data synchronization takes a very short period. This value is used when the service load is light. Custom: User-defined synchronization speed. The value ranges from 1 MB/s to 1024 MB/s.
   Recovery Policy	Determines how data is synchronized after a fault is rectified. Automatic: The system automatically synchronizes data. Manual: Data must be synchronized manually.
   Initial Sync	Initial synchronization mode of local and remote resources. When Pair Creation is set to Automatic, the value can be: Automatic: The system automatically synchronizes data between the local and remote resources upon pair creation. Manual: Data must be manually synchronized between the local and remote resources. When Pair Creation is set to Manual, the value can be: If data is inconsistent: Automatic: The system automatically synchronizes data between the local and remote resources upon pair creation. Manual: Data must be manually synchronized between the local and remote resources. If data is consistent, synchronization is not required.

   It is recommended that you perform synchronization tests for different speeds and select a proper speed based on the test result. Choose a faster speed as long as the bandwidth is sufficient.

7. Click Next.
8. Configure the mapping.

   The LUNs at both ends of a HyperMetro pair must be mapped to the same host. You can enable Map to Same Host or Host Group to quickly create the mapping.

   1. Enable Map to Same Host or Host Group.
      • When LUNs are mapped to the same host or host group, the initiator information of the hosts to which the HyperMetro LUNs are mapped must be the same on the local and remote storage systems.
      • If you want to map LUNs to different hosts, disable Map to Same Host or Host Group and configure the mappings for the local and remote LUNs separately.
   2. Select a host or host group to which you want to map the LUNs.

      In no host or host group is available, click Create to create one.

   3. (Optional) Select Local Port Group.

      After a port group is selected, LUNs in the LUN group use the ports of the port group to communicate with hosts in the host group. If no port group is selected, available ports are randomly used.

   4. Set Host LUN ID. This can be specified automatically or manually. If you select Manual, specify a host LUN ID ranging from 0 to 4095.
   5. Specify Host Access Mode. Possible values are Load balancing or Asymmetric.

9. Click Next.

   A summary is displayed.

10. Confirm the HyperMetro information and click OK.

    Confirm your operation as prompted.