HP MSA Controllers User Manual
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HP P2000 G3 FC/iSCSI MSA System User Guide
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Connecting two storage systems to replicate volumes
Remote Snap replication is a licensed disaster-recovery feature that performs asynchronous (batch)
replication of block-level data from a volume on a primary P2000 G3 MSA System to a volume that can
be on the same system, or on a second, independent P2000 G3 MSA System. The second system can be
located at the same site as the first system, or at a different site.
The two associated master volumes form a replication set, and only the primary volume (source of data)
can be mapped for access by a server. Both systems must be licensed to use Remote Snap, and must be
connected through switches to the same fabric or network (i.e., no direct attach). The server accessing the
replication set need only be connected to the primary system. If the primary system goes offline, a
connected server can access the replicated data from the secondary system.
Replication configuration possibilities are many, and can be cabled – in switch attach fashion – to support
P2000 G3 MSA Systems on the same network, or on physically split networks. As you consider the
physical connections of your system – specifically connections for replication – keep several important
points in mind:
•
Ensure that controllers have connectivity between systems, whether local or remote.
•
Assign specific ports for replication whenever possible. By specifically assigning ports available for
replication, you free the controller from scanning and assigning the ports at the time replication is
performed.
•
For remote replication, ensure that all ports assigned for replication are able to communicate
appropriately with the remote replication system (see verify remote-link in the CLI reference guide for
more information).
•
Allow two ports to perform replication. This permits the system to balance the load across those ports as
I/O demands rise and fall. On dual-controller enclosures, if some of the volumes replicated are owned
by controller A and others are owned by controller B, then allow one port for replication on each
controller module of P2000 G3 FC MSA Systems, and possibly more than one port per controller
module on P2000 G3 FC/iSCSI MSA Systems, depending on replication traffic load.
•
Be sure of the desired link type before creating the replication set, because you cannot change the
replication link type after creating the replication set.
•
Do not unnecessarily expose the controller module’s network port to an external network connection.
Conceptual cabling examples are provided addressing cabling on the same network and cabling relative
to physically-split networks. Both single and dual-controller environments support replication. A
single-controller system can replicate data to another single-controller system, and a dual-controller system
can replicate data to another dual-controller system. Replication services do not support mixed single and
dual-controller environments.
CAUTION:
When replacing a P2000 G3 MSA System controller set supporting Remote Snap with a
P2000 G3 MSA System controller set that does not support this licensed feature (i.e., SAS controller
modules), you must first delete all replication sets before swapping the controller modules. Not doing so
will lead to unexpected results, and there is not way to delete replication sets after the installation. See the
upgrade documentation supporting your product.
IMPORTANT:
Remote Snap must be licensed on all systems configured for replication, and the controller
module firmware version must be the same on all systems licensed for replication (see