Network I/O controls together with Network Resource Pools allow for a sophisticated management of all the traffic types available on a Distributed Switch. There are number of built-in Network Resource Pools, as well the capacity to create user-defined pools. There built-in pools support the following traffic types:
- Fault Tolerance
- vSphere Replication (VR)
- Virtual Machine
The settings on these “System” Network Resource Pools can be modified – and no work has been done to assign them to a portgroup. VMware ESXi automatically recognises the traffic type leaving the host, and assigns the settings. By default all traffic is treated equally, except for Virtual Machine traffic which is given a share value of “High”.
These default settings can be adjusted to affect the traffic.
Optionally, user-defined Network Resource pools allow the administrator to define their own pools – and configure the custom settings. This consists of a proportional “share” value. This is a settings is usually configured with parameters of Low, Normal, Medium and High. A custom option allows allocation of a number such as 100. The label or numerical allow to set a high allocation of resources dependent on contention. Under normal operations when network resources are not scarce, the traffic types are able to use as much of the bandwidth available. However, when contention kicks in because of a lack of bandwidth the share system guarantees a predictable outcome. Typically, administrators allocate a higher share value to mission critical traffic such as iSCSI, NFS, Management and Virtual Machines – whereas ancillary traffic which is more expendable and used in background process such as vMotion or vSphere Replication. In addition to the share allocation, these built-in network resource pools an allocation of bandwidth can be granted per traffic type.