Removing pNIC from vDS

[warnox]

Hi,

I'm wondering what will happen to any VM's that are using a certain pNIC though a vDS when that NIC is removed from a vDS or unplugged from the server? How long does it take for vCenter to realise something has happened and it migrates the VM to another pNIC?

I cannot find any official information regarding this and I'm not able to test it at the moment

Thanks for any help.

[Anjani_Kumar]

Well. nice Question. As soon you will remove the Nic from the server the HA Agent will start hitting the host first and if it doesnt respond thant it will reach to the default gateway of the server.

After 13-14 Attempt and isolate the host from the HA and all the vms will start rebooting to the next available host. 

I believe it should not take more than 1-2 minutes to initiate the failover.

[warnox]

Ah, sorry, should've specified that the host has 3 NIC's, and I'm just removing one from the vDS...

[rcporto]

I think the traffic will be routed through another active uplinks is few seconds, but your physical network design should impact in this time, because ARP address for VMs should be update on CAM of physical switches and because of this, each environment will have different times.

[Anjani_Kumar]

Here you need to be more specific. Have to check it out if you are removing the nic which is used as management network / vm port group/ or vmotion or FT.

Here are the impact being specific to nic    

Management. : Than your esx will be disconnect immediately and initiate a failover if you didnt added a Redundant nic in to it.  else it will work if a single nic is disconnected.

vm port group : the machine will start rebooting and move to the next host immed. same as management network

vMotion port : if you disconnected it will not give you any impact. only migration of machines due to DRS or manual will stop working.

i hope you are now cleared about it.

[Abukar]

That all depends on what you are using for the nic.If your nics is configured to fail over to other active nics then yes the traffic will be routed as soon as the host deducts link failure.

[warnox · Accepted solution]

Alright, so I went and tested this. With an active SSH session to one host displaying esxtop (network) I removed one (of 3) NIC from the vDS. Instantaneously the VM's which were on this NIC were moved to another one. I had a continuous ping running to these VM's prior to making the change and not even one ICMP request timed out (so if the connection did drop it was for less than 1 second). The physical switch (a Cisco in this case) also updated it's CAM table instantly, although as Richardson pointed out, that might depend on the hardware/network configuration.

Thanks for all your responses.