8 weeks of #VCAP – vSphere Network I/O Control

Alright – here we go, Network I/O Control – Objective 2.4 of the blueprint lists this as a skill you must know.  Honestly, I've never used this before writing this post…thankfully, it's a very very easy thing to configure.  Unless I'm missing something, in which case I'm in for some trouble come exam time πŸ™‚

First up, let's have a look at the requirements.

  • Enterprise Plus licensing – since you need a distributed switch to use NIOC, in turn you need Ent+ licenses.

OK, maybe I should of said requirement – not plural.  I can't seem to find any other requirements for using NIOC.  Anyways, the first step in getting NIOC setup is to enable it, and this in itself is a matter of checking a box.  From within the Networking inventory view on the Resource Allocation tab select ‘Properties’ and check the box πŸ™‚



System Network Resource Pools

Easy enough right!  Now on to our Network resource pools.  As you can see, there are some default system network resource pools already setup within NIOC.

  • Fault Tolerance
  • iSCSI
  • Management Traffic
  • Virtual Machine Traffic
  • vMotion
  • vSphere Replication

I’ll leave it to your imagination as to what traffic these represent.  Basically these resource pools are automatically applied to their corresponding traffic type when we enable NIOC.   NIOC utilizes the same type of sharing mechanism that resource pools utilize.  Meaning each resource pool is assigned a share value, one that will apply relatively to the other pools during network contention.  Thus, if going by the example in the Networking guide, if we assign FT and iSCSI a share value of 100, while all other resource pools having 50 shares, iSCSI and FT would each get 25% while the remaining resource pools would receive 12.5% of the available bandwidth (during contention).  The table below should help with that formula

Resource Pool Shares Total Shares Percentage
iSCSI 100 400 25%
FT 100 400 25%
Management 50 400 12.5%
VM 50 400 12.5%
vMotion 50 400 12.5%
Replication 50 400 12.5%

What if I want to further segregate my VM traffic?

A valid question.  To resolve this NIOC allows us to create our own User-defined network resource pools. Again, this is a very easy process.  Selecting ‘New Network Resource Pool’ will get the dialog box open that we need.  See Below..


As you can see, we can create our own resource pool, assign either a predefined (high, normal, low) share value to it (or we can set a custom number) as well as a QoS priority tag if we need to tag outbound QoS from our virtual switch.  Just a note, we can change the values and QoS tags on our system defined resource pools as well if need be.

Now that we have our resource pool created there’s only one final step in applying it.  Using the ‘Manage Port Groups’ link we can assign our newly created resource pool to one of our dvPortGroups.  Below I’ve done just that by assigning ‘My Server Traffic’ to dvServers.


And that’s all there is to NIOC really.  Again, not too hard, but something I’ve never touched before now.  Also, something that could of caught me off guard on the exam – the last thing i want to do is spend time reading documentation!  Good luck studying!