Ensure that you are familiar with the constraints for zoning
a switch to support the Metro Mirror and Global Mirror feature.
SAN configurations that use intrasystem Metro Mirror and
Global Mirror relationships do not require more switch zones.
You can zone Fibre
Channel over Ethernet (FCoE) ports on system 1 with Fibre Channel
(FC) ports of system 2 or FCoE ports on system 1 with FCoE ports on
system 2 to support Metro Mirror and Global Mirror replications.
For intersystem Metro Mirror and Global Mirror relationships, you
must complete the following steps to create the additional zones that
are required:
- Configure your SAN so that Fibre Channel traffic can be passed between the two clustered systems. To configure the SAN this way, you can connect the systems
to the same SAN, merge the SANs, or use routing technologies.
- Optional: Configure zoning to enable
the nodes in the local fabric to communicate with the nodes in the
remote fabric.
For Metro Mirror and Global Mirror configurations where the round-trip latency between systems
is less than 80 milliseconds, zone two Fibre Channel ports on each
node in the local system to two Fibre Channel ports on each node in
the remote system. If dual-redundant fabrics are available, zone
one port from each node across on each fabric to provide the greatest
fault tolerance. No other Fibre Channel ports on any node should
have remote zones.
If
the round-trip latency between systems is greater than 80 milliseconds,
stricter configuration requirements apply:
- Use SAN zoning and port masking to ensure that two Fibre Channel
ports on each node that is used for replication are dedicated for
replication traffic.
- Apply SAN zoning to provide separate intersystem zones for each
local-to-remote I/O group pair that is used for replication. See the
information about long-distance links for Metro Mirror and Global
Mirror partnerships for further details.
- Optional: As an alternative to step 2,
choose a subset of nodes in the local system to be zoned to the nodes
in the remote system. Minimally, you must ensure that one whole I/O
group in the local system has connectivity to one whole I/O group
in the remote system. I/O between the nodes in each system is then
routed to find a path that is permitted by the configured zoning.
Reducing the number of nodes that are zoned together can reduce the
complexity of the intersystem zoning and might reduce the cost of
the routing hardware that is required for large installations. Reducing
the number of nodes also means that I/O must make extra hops between
the nodes in the system, which increases the load on the intermediate
nodes and can increase the performance impact; in particular, for Metro Mirror.
- Optional: Modify the zoning so that the hosts that are visible
to the local system can recognize the remote system. This zoning enables
a host to examine data in both the local and remote system.
- Verify that system A cannot recognize any of the back-end storage
that is owned by system B. A system cannot access logical units (LUs)
that a host or another system can also access.