vMotion requires, at a minimum, a single, active, 1 GB network adapter. A second standby adapter should be configured to provide redundancy for the vMotion network.

A vMotion migration can consume all of the available network bandwidth. If the vMotion network is shared with other network traffic, traffic shaping or NIOC should be enabled to prevent vMotion from impacting other virtual network traffic. If possible, vMotion should be configured on a separate physical network or separate VLAN.

vSphere 5 introduced the ability to configure multiple adapters for use with vMotion. Multiple-NIC vMotion allows for the bandwidth of multiple physical NICs to be leveraged by vMotion to speed up the migration of virtual machines between hosts.

To configure Multiple-NIC vMotion, create multiple VMkernel interfaces with vMotion enabled. Configure each VMkernel interface to use a single active adapter, and configure other available adapters as standby adapters. When a virtual machine is vMotioned, either manually or by DRS, all available links will be used for the vMotion traffic. More information on Multiple-NIC vMotion can be found in the VMware Knowledge Base article at http://kb.vmware.com/kb/2007467.