Each clustered system that uses SAN fabric switches can use shortwave or longwave
optical fiber connections connect to application hosts, storage systems, or remote systems.
The maximum distance between the system and host
or the system and the storage system depends on the Fibre Channel speed and cable type. For
all speeds and cable types, the maximum distance is 300 m for shortwave
optical connections and 10 km for longwave optical connections. Longer distances are supported
between systems that use the intersystem Metro Mirror or Global Mirror feature.
When you use longwave optical
fiber connections, follow these guidelines:
- For disaster recovery, each system must be regarded
as a single entity, which includes the storage system that provides the quorum disks for the system. Therefore,
the system and quorum disks must be co-located.
The maximum distance between nodes within a system is 100 meters. There can be a large fibre-cable
distance between the same nodes in the system. The nodes, however, must be physically co-located for effective service and
maintenance.
For example, the nodes can be 300 meters away for 2 Gbs connections. For 4 Gbs connections, nodes can be 150 meters away for m the SAN fabric. In both configurations,
there is a maximum of 600-meters cable distance between the nodes. However, the nodes must be physically within 100
meters of each other.
- All nodes in a system must be on the
same IP subnet so that the nodes can assume the same system
or service IP address.