Converting the system between the storage and replication layers

If you are adding an iSCSI-attached external storage system to an existing configuration, then the source system must be in the replication layer to initiate connections to the new storage.

The system can be configured in 1 of 2 system layers: the replication layer or the storage layer. The replication layer contains systems that are primarily used for host I/O operations. Systems in the replication layer have the following characteristics:
  • The system can use other systems in the storage layer for external storage and virtualization.
  • The system can complete remote-copy replication with other systems in the replication layer.
  • The system cannot provide external storage for other systems in the replication layer.
Systems in the storage layer provide the underlying storage that the system within the replication layer use for virtualization. Systems in the storage layer have the following characteristics:
  • The system can provide external storage for system in the replication layer.
  • The system can complete remote-copy replication with other systems in the storage layer.
  • The system cannot use another system that is configured in the storage layer as external storage.

These system layers are created when the storage area network is configured and zoned correctly. If the zone configuration is completed, then adding a system to your configuration can require changes to ensure that the system is added to the correct system layer.

If you are adding an iSCSI-attached external storage system to an existing configuration, the source system must be in the replication layer to initiate connections to the new storage. Because the system automatically is added to the storage layer, you must convert the system to the appropriate system layer before you add the target system as external storage. If the system is used to initiate connections to an iSCSI-attached external storage system, it must be in the replication layer. If the system is being used as external storage, it must be added to the storage layer.

Before you can convert the system to the replication layer, you must ensure that the following tasks are completed, otherwise the conversion fails:
  1. Ensure that no host objects with worldwide port names from the system by completing these steps:
    1. In the management GUI, select Hosts > Hosts
    2. Right-click the host to be removed and select Unmap All Volumes.
    3. Right-click the host and select Remove.
    4. After the hosts systems are removed, reconfigure zoning so that the system is no longer accessible to the host as storage. The host zone must also be reconfigured so all previous connections are removed.
  2. Ensure that all existing partnerships on both the local and remote system are deleted by completing these steps:
    1. Verify that the partnership does not use any remote-copy relationships or consistency groups. If relationships or consistency groups are used, delete them before you delete the partnership. In the management GUI, select Copy Services > Remote Copy or Copy Services > Consistency Groups.
    2. To delete the partnership, select Copy Services > Partnerships.
    3. Right-click the partnership and select Delete.
    4. Repeat this step for both the local and remote systems for all existing partnerships.
  3. Remove the connectivity between nodes in the local system and the remote system. This task requires changing configuration on switches. Consult documentation for your switch for details.
Parent topic: Adding Storwize family external storage system
Contents | Monitoring | Pools | Volumes | Hosts | Copy Services | Access | Settings | More Information