VCP5 mock test question, question re: networking @ 10Gb

[jreininger]

The VCP5 VMware mock test has a question about a VM host using 900 Mbps of network bandwidth. The answer (it appears) is the ESXi host NIC is being over used.

However, the mock test does not say the host has (only) a 1 Gb Ethernet NIC in it. If the host had a newer 10 Gb NIC, the answer would then be wrong or the question would needed to be modified correct?

This sparked me to start looking at my VMs connection speeds to my vSS (virtual standard switches), they all seem to be limited ot 1GB.

Then when I refer to the "Master VMware vSphere 5" book by (page 214) Scott Lowe" it says:

vmxnet is a 1Gpbs virtual networking adapter
Intel e1000 is a 1Gpbs networking adapter

I do recall from past reading all vNIC on same host will operate as fast as the VMkernel can process local traffic.

BUT if you had a 10Gb NICs from host to host would the fact the vNICs are limited to 1Gb actually become a bottle neck?..
ie how can you exceed the 900 Mbps from host to host from a VM (without using PCIe pass-though) if you had 10Gb Ethernet NICs in your hosts?

Would PCIe pass-though work? I know most disks on either side of a single VM would likely never need that bandwidth.

Perhaps a newer/newest version of the vmxnet does allow for 10Gb local vSwitch connections (and visalbe in the windows vNIC properites?

Thanks.

Jonathan Reininger

[jreininger]

Oh I now see the VMXNET3 on a Win7 64bit VM does show as a 10Gb connection..

It seems Scott Lowes's book is not differentiating between VMXNET2 and VMXNET3, or perhaps VMXNET2 can also do 10 Gb?

[jose_maria_gonz]

Hi Jreininger

My understanding was that VMXNET2 could do 10G as well but i could be wrong now.

I hope I have helped you out

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[Josh26]

It's a representation of the real exam.

You need to assume there is something in the question to lead you to the answer, and there is nothing in the mock question suggesting CPU or memory are at a premium. I appreciate that this may involve an invalid assumption, but if you don't make it, none of the answers are proveably correct.

[Shoganator]

I remember this question when I took the mock exam a week or so ago - I was also thinking along the same lines as you Jonathan, but after considering the lack of any other information I made the assumption that the Host had a 1Gbit pNIC and therefore chose my answer based off that assumption. I do agree however that perhaps the question should have been a little clearer or perhaps provided an exhibit with a command line output of physical adapters in the host

Perhaps they thought that would make things too easy though - sometimes "exam" ethic is required on the candidates part, and this is where your exam technique / logic comes into play. Well, that is my theory anyway!