A direct-attached configuration dedicates entire port bandwidth
to be used for a specific connection. Planning must account for the
volume of expected traffic before you decide how many ports are used
in a direct-attached configuration.
The system offers multiple options in deciding how to create a direct-attached configuration.
Bandwidth requirements for a direct-attached configuration make it important to determine the volume
of expected traffic in deciding the number of ports. For example, if a system to
system direct-attached link is configured between nodes in an I/O group, then this link carries
cache replication traffic. Hence, enough system to system bandwidth needs to be available so that
cache replication for host writes can occur without any bandwidth bottleneck.
The following guidelines are provided for direct-attached configurations.
Note: One or more Fibre
Channel host adapters must be installed for the system to support these direct attachment
configurations.
- Fibre Channel direct attachment to host systems.
The system allows direct attachment
connectivity between its Fibre Channel ports and host ports. Host systems can be connected to 8 Gb or 16 Gb Fibre Channel ports on the system. No special configuration is needed
for host systems that are using this configuration.
- Fibre Channel direct attachment between nodes in a system.
Direct connection of the system
Fibre Channel ports without using a Fibre Channel switch is supported. Such direct connections
between the system nodes might be useful in small configurations where no Fibre Channel switch
exists. It can also be used to connect nodes in the same I/O group to
provide a dedicated connection for mirroring the fast write cache data. Ensure that sufficient
bandwidth is provisioned between nodes to accommodate all the intra-node traffic.
SAN Volume Controller 2145-DH8
supports 16 Gb Fibre Channel ports.
Node to host and node to node direct
attachment is supported on all 16 Gb Fibre Channel ports.