Saturday, April 9, 2011

Default vNIC Type in vSphere 4.1

vSphere/vCenter 4.1 automatically sets vNIC (vritual NIC) type to be Flexible when a new VM is created, one is resulted after a P2V operation using VMware converter, or when one is upgraded to Virtual Hardware Version 7. 

This may have adverse effects on a VM if drivers are not loaded correctly during or after booting up a VM. We noticed that a couple of our VMs were timing out in our environment and this was fixed by changing the adapter type e1000.

You can find more about VMware vNIC types here,

For production environments, I recommend using e1000 even though your VM may eat up a few CPU cycles.