How does vmkping work?

[vmproteau]

I have a couple ESX servers that will be setup for VMotion as soon as the SAN arrives. I've pre-configured the VMKernel vSwitch and wanted to test to see if it is correct.

What kind of checks does vmkping do? It fails so, I'm wondering if it checks for shared storage. If it does I may have to wait to verify the network.

I was able to verify cold migration over the network is working.

[RParker · Accepted solution]

The vmkping ensures that a VMkernel network can reach the SAN and the ping ensures the service console can reach the SAN. Both must be able to network to the SAN to log into new volumes

[admin]

Hello,

vmkping is a command to test kernel network. The syntax is : vmkping IP_ADRESS (don't use DNS)

[wila]

You are mentioning that vmkping fails, but not how it fails.

If you are on 3.0.2, then you might want to check out this update:

http://kb.vmware.com/kb/1002424

[vmproteau]

I just get 100% packet loss although cold migrations work fine. I think answered this for me. I believe the network configuration is fine however; I won't be able to know for sure until I have the SAN in place.

[patrickds]

For VMotion to work, your vmkping between the hosts should be successful. SAN connectivity plays no part in this (unless it is a NAS you're talking about)

A vmotion will hot migrate a VM over the VMkernel network, if vmkping reports a 100% loss you wil not be able to perform a vmotion either.

Better sort this out before you actually need it.

Cold migrations go over the service console network.

[koleong]

HI ,

Isn't possible use this command ping iscsi target ?

My esx server3.5 update 3 vnic1 (vmkernel)=172.16.1.22

NetApp filer FAS2020 IP = 172.16.1.11

#vmkping 172.16.1.11 (on the service console)

OR

#ping 172.16.1.11

Thanks

LeongKO

[scotty_p]

That's a great article. I wish I would have found it before we did our upgrades. The ghost NIC was the one that got us. It was putting entries into DHCP. At least now I can do some clean up. Thanks.