Holy crap what do all these VMware VMkernel type mean?  I started this article and realized I had already written one here.  Sad when google leads you to something you wrote… looks like I don’t remember too well… Perhaps I should just go yell for the kids to get off my lawn now.   I wanted to take a minute to revise my post with some new things I have learned and some guidance.

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From my previous post:

  • vMotion traffic – Required for vMotion – Moves the state of virtual machines (active datadisk svMotion, active memory and execution state) during a vMotion
  • Provisioning traffic – Not required will use management network if not setup – cold migration, cloning and snapshot creation (powered off virtual machines = cold)
  • Fault tolerance traffic (FT)  – Required for FT – Enables fault tolerance traffic on the host – only a single adapter may be used for FT per host
  • Management traffic – Required – Management of host and vCenter server
  • vSphere replication traffic – Only needed if using vSphere replication– outgoing replication data from ESXi host to vSphere replication server
  • vSphere replication NFC traffic – Only needed if using vSphere replication – handles incoming replication data on the target replication site
  • Virtual SAN – Required for VSAN – virtual san traffic on the host
  • VXLAN – used for NSX not controlled from the add vmkernel interface.

I wanted to provide a little better explanation around design elements with some interfaces.  Specifically I want to focus on vMotion and Provisioning traffic.    Let’s create a few scenario’s and see what interface is used assuming I have all the VMkernel interfaces listed above:

  1. VM1 is running and we want to migrate from host1 to host2 at datacenter1 – vMotion
  2. VM1 is running with a snapshot and we want to migrate from host1 to host2 at datacenter1 – Provisioning traffic (if it does not exist management network is used)
  3. VM1 is running with a snapshot and we want to storage migrate from host1 DC1 to host4 DC3 – storage vMotion – Provisioning traffic (if it does not exist management network is used)
  4. VM1 is not running and we want to migrate from host1 to host2 at datacenter1 – Provisioning traffic (very low bandwidth used)
  5. VM1 is not running has a snapshot and we want to migrate from host1 to host2 at datacenter1 – Provisioning traffic (very low bandwidth used)
  6. VM2 is being created at datacenter1 – Provisioning traffic

 

So design guidance in a multi-site implementation you should have the following interfaces if you wish to separate the TCP-IP stack  or use network IO control to avoid bad neighbor situations.   (Or you could just assign it all to management vmk and go nuts on that interface = bad idea)

  • Management
  • vMotion
  • Provisioning

Use of other vmkernel interfaces depends on if you are using replication, vSAN or NSX.

Should you have multi-nic vMotion? 

Multi-nic vMotion enables faster vMotion of multiple entries off a host (as long as they don’t have snapshots).   It still is a good idea if you have large vm’s or lots of vm’s on a host.

Should you have multi-nic Provisioning?

No idea if it’s even supported or a good idea.  Provisioning network is used for long distance vMotion so the idea might be good… I would not use it today.

© 2016, Joseph Griffiths. All rights reserved.

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