Post RASR Reset of VxRail 4.7 Host Re-Add Host into Additional Virtual Distributed Switch (vDS)

As I’m sure many of you are aware VxRail Manager is only responsible for the virtual distributed switch it creates at install.  What about any additional vDS that you create?  You are 100% responsible for their upgrade and management.  It doesn’t sound so bad right?  How often do we actually interact with a vDS?  Here is a gotcha I discovered helping others troubleshoot network issues following a RASR reset of a host that gets re-added into the existing cluster.

Scenario

You are having issues with a VxRail host and support determines a RASR (factory) reset is the only solution.  Following the RASR reset you will add the host back into the cluster and hopefully that resolves your issues.  Yes, it does! Awesome!  The host & cluster even pass their health checks.  Later on you choose to vMotion a VM manually and it is unable to vMotion to the recently re-added host.

Cause:

When the host was RASR reset the additional virtual distributed switch that you manually added the host to was put back.  The vMotion failed because it couldn’t see the network on the target (re-added) host.

Solution:

Go into the vDS and re-add the missing host.

How to re-add a host to an existing vDS

Go to the vDS you wish to add the host back into

Select Add and Manage Hosts

Add Host

Select New hosts

Select the host you want to re-add

Assign the uplink to the vmnic and have it match what you previous had I your environment.

Summary:
As you can see it is a pretty easy process.  The challenge is catching it during the host being re-added into the cluster to avoid the problem all together.  As always, I hope y’all found this helpful.