System layers

An LenovoStorwize® family system is in one of two layers: the replication layer or the storage layer.

The system layer affects how the system interacts with SAN Volume Controller and external Storwize family systems.

Differences between the storage layer and the replication layer

In storage layer, a Storwize family system has the following characteristics and requirements:
  • The system can complete Metro Mirror and Global Mirror replication with other storage-layer systems.
  • The system can provide external storage for replication-layer systems or SAN Volume Controller.
  • The system cannot use another Storwize family system that is configured with storage-layer as external storage.
In replication layer, a Storwize family system has the following characteristics and requirements:
  • The system can complete Metro Mirror and Global Mirror replication with other replication-layer systems or SAN Volume Controller.
  • The system cannot provide external storage for a replication-layer system or SAN Volume Controller.
  • The system can use another Storwize family system that is configured with storage-layer as external storage.

A Storwize family system is in the storage layer by default, but the layer can be changed. For example, you might want to change a Lenovo Storage V7000 system to a replication layer if you want to use it to complete Global Mirror or Metro Mirror with a SAN Volume Controller system.

Changing the layer of a Storwize family system

Before you change the system layer, the following conditions must be met:
  • No host object can be configured with worldwide port names (WWPNs) from a Storwize family system.
  • No system partnerships can be defined.
  • No Storwize family system can be visible on the SAN fabric.

The layer can be changed during normal host I/O.

To change the layer of a system, follow these general steps:
  1. Use the svc_lssystem.html#chsystem command to check the current system layer.
  2. Configure SAN zoning so that the system whose layer you are changing is not visible to any other system.
  3. Ensure that all other configuration requirements are met.
  4. Run the svc_requestdiscovery_21ifux.html#lsvc_requestdiscovery_21ifux command to ensure that the system detects any fabric changes that were done in step 3.
  5. Enter chsystem to switch to the replication layer or chsystem to switch to the storage layer.
  6. If the SAN configuration was changed in step 2, restore the normal SAN configuration.
  7. Run the svc_requestdiscovery_21ifux.html#lsvc_requestdiscovery_21ifux command to update the list of MDisks.
Parent topic: Technical overview
Related concepts
Configuring LenovoStorwize V3500 or Storwize V3700 external storage systems
Configuring IBMLenovo Storage V7000, Lenovo Storage V7000 Unified, or Flex System V7000 Storage Node external storage systems
Metro Mirror and Global Mirror partnerships