In an earlier post in April, titled, “Which NIC is my VM using"? Load Balancing Visibility with vSphere”, I described how esxtop could reveal the active (or hashed) vmnic for a VM or vmkernel port. Early vSphere 4 customers have found this an extremely useful feature, however, in my description, I completely ignored ESXi (sorry!).
Ok, so how do you do esxtop on ESXi? This is where vMA (the VMware Management Assistant—formerly called VIMA) and resxtop come in. vMA is a VM containing a prepackaged installation of the vCLI (vSphere Command Line Interface), which allows admins to run scripts and agents for managing ESX and ESXi hosts (yes, both!). Within the vMA VM, you run the resxtop command, then type “n” to show what vmnics are used by what VMs and vmkernel ports.
Note that you an also download vCLI as standalone software and install it on your own system.
Another neat thing is that you can quickly and easily deploy vMA to an ESX or ESXi host with the “Deploy from URL” wizard within the vSphere Client. Just point it at: http://www.vmware.com/go/importvma/vma4.ovf to download the ovf.