Each modern CNA port provides 10Gbps of bandwidth per port. It makes sense to allow partitioning that bandwidth across various tasks rather than being forced to allocate it to one task per port. This makes even more sense when we consider that each port requires a dedicated physical Ethernet cable, and ensuring 100% usage of the capacity of each cable makes costs go down and maintenance easier.
The NIC Partitioning feature of CNAs allows administrators to organize multiple tasks on each port and intelligently distribute the full capacity of each port’s total bandwidth across the various partitions.
In theory, NIC Partitioning only splits the bandwidth of a port into multiple portions. However, the concept is analogous with hard drive partitioning, where each partition splits the disk space into multiple portions, but each portion then shows up as a "mini" hard drive that can be treated the same as the full drive itself.
Similarly, each partition of a CNA port behaves like a "mini" port and can take up one or more personalities. Each personality of the partition further shows up as an individual entity which can then be configured to address specific needs in the operating system. Each partition performs according to the portion of bandwidth allocated to it and administrators can ensure the quality of service on certain partitions over others by such intelligent allocation of bandwidth.
There are two aspects to configuring bandwidth allocation: minimum bandwidth and maximum bandwidth. To find out more, see the white paper located here.
Additionally, iDRAC with Lifecycle Controller technology offers the remote ability to configure the CNA bandwidths. Best practice workflows and scripts are available here.