IBM System Storage DS3000 Programming Manual page 466

Activating the Enhanced Global Mirroring premium feature
After you activate the premium feature, the secondary ports for each controller are reserved and
dedicated to remote mirror use. Any host-initiated I/O operation is not accepted by the dedicated port,
and any request received on the dedicated port is accepted only from another controller participating in
the mirror relationship.
To activate the Enhanced Global Mirror premium feature, use this command:
activate storagesubsystem feature=enhancedGlobalMirror
The storage subsystem performs the following actions when you activate the Enhanced Global Mirroring
premium feature:
v Logs out all hosts currently using the highest numbered Fibre Channel host port on the controllers.
v Reserves the highest numbered Fibre Channel host port on the controllers for mirror data
transmissions.
v Rejects all host communication to this controller host port as long as the Enhanced Global Mirroring
premium feature is active.
After you activate the Enhanced Global Mirroring premium feature, you must set up an Enhanced Global
Mirror Group and an Enhanced Global Mirror pair.
Creating the Enhanced Global Mirroring group
An Enhanced Global Mirror Group contains several mirrored pairs so that they can be managed as a
single entity. You create an Enhanced Global Mirror Group to define the synchronization settings for all
mirrored pairs within the group. Each mirrored pair in an Enhanced Global Mirror Group shares the
same synchronization settings, primary role, secondary role, and write mode.
The Enhanced Global Mirror Group is associated with the local storage subsystem and remote storage
subsystem that is used for mirroring. The local storage subsystem is the primary side of the Enhanced
Global Mirror Group, while the remote storage subsystem is the secondary side of the Enhanced Global
Mirror Group. All logical drives added to the Enhanced Global Mirror Group on the local storage
subsystem hold the primary role in the mirror relationship. Subsequently, all logical drives added to the
Enhanced Global Mirror Group on the remote storage subsystem hold the secondary role in the mirror
relationship.
Guidelines to follow when creating an Enhanced Global Mirror Group:
v A storage subsystem has a maximum number of Enhanced Global Mirror Group. The maximum
number of Enhanced Global Mirror Groups depends on your configuration
v Enhanced Global Mirror Groups are created empty and Enhanced Global Mirror pairs are added to the
groups later. You can add only Enhanced Global Mirror pairs to an Enhanced Global Mirror Group.
Each mirrored pair is associated with exactly one Enhanced Global Mirror Group.
v All storage subsystems with the Enhanced Global Mirroring premium feature activated are listed and
can be used for mirror activities.
v Storage subsystems are displayed by their storage subsystem name. If a storage subsystem does not
have a name, the storage subsystem is displayed as "Unnamed".
Ensure that you run the Create Enhanced Global Mirror Group command on the local storage subsystem.
Enhanced Global Mirror Group creation is initiated from the storage subsystem that contains the logical
drives that hold the primary role in the mirror relationship. You use the Create Enhanced Global Mirror
Group command to specify the remote storage subsystem that contains the logical drives that will provide
the secondary role in the mirror relationship.
The command has this form:
7-6
IBM System Storage DS3000, DS4000, and DS5000: Command Line Interface and Script Commands Programming Guide