Link aggregation

Network Administration Guide for Hitachi NAS Platform

Part Number

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 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.

To view the status of an aggregation, navigate to the Link Aggregation page as shown below:

Note: Models 5200/5300 and the NAS module support up to six link aggregations. Models 4060/4080/4100 support up to four aggregations. Models 4040 and earlier support up to eight aggregations.