Hitachi 3100, Network Administration Manual

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File serving interfaces
NAS servers provide the following file serving physical interfaces:
Models 4040 and earlier
• ge1 - ge6 - 1 GbE interfaces (RJ45)
• tg1 - tg2 - 10 GbE interfaces (XFP)
Models 4060 / 4080 / 4100
• tg1 - tg4 - 10 GbE interfaces (SFP+)
File serving physical interfaces enable network clients to access an EVS on
the storage server. These interfaces are commonly added together in a link
aggregation in order to increase redundancy and throughput of data.
Link aggregation
In a link aggregation, one or more file serving interfaces are grouped to form
a single logical interface. This functionality can increase bandwidth capability
and create resilient and redundant links. Aggregating multiple network links
does not increase performance of a single client TCP connection but it does
enable more individual connections to be served faster, by using more
available links and also by reducing contention within a link. An aggregation
also provides load balancing where the processing and communications
activity is distributed across several links in a trunk. Therefore, aggregations
provide higher link availability and increased Link Aggregation Group (LAG)
capacity.
Note: All interfaces in an aggregation must be of the same type/speed
(either all 1 Gbps interfaces or all 10 Gbps interfaces).
An aggregation is assigned a unique MAC address which is different on each
cluster node. Each aggregation can have multiple IP addresses. It is possible
to configure an aggregation without any IP addresses, but this prevents
communication through that interface. For example, in a cluster, an
aggregation associated with an EVS appears on all nodes but is only active on
the node that the EVS is running on because the EVS holds the IP address. If
the EVS fails over onto another node, the IP address moves with the EVS,
activating the aggregation on the new node.
The server supports static aggregations. It also supports the Link
Aggregation Control Protocol (LACP) for dynamic aggregations.
Network interfaces 15
Hitachi NAS Platform Network Administration Guide