So what happens if one of the VM’s impacted by this problem is v Center?

It is recommended that you protect v Center with available and supported high availability solutions such as v Center Heartbeat, in a WAN configuration to protect against local site power outage.

Recently my colleague Venky Deshpande released a whitepaper around VDS Best Practices.

Updating vcenter vds data video

In the past the workaround solution that I implemented was to reboot the host.

Provided the storage had been restored before the host had been booted, then any VM’s could then be connected back to the network (including v Center it it was one of the VM’s impacted). Fortunately Duncan has found it is as simple as restarting the management services on the host by executing “restart” at the ESXi Shell (5.0), or Tech Support Mode (4.x).

Duncan has posted a follow up to his original article titled Digging Deeper into the v DS Construct.

This outlines the problem again and also a workaround solution.

I powered of a VM and checked the “Network settings and this is what it revealed…

a port already assigned even when powered off: This is not the only place you can see port assignments, you can verify it on the VDS’s “ports” tab: Now lets test this, as that is ultimately what it is all about.This is what allows the v Sphere Hosts to work completely independently of v Center.If v Center is unavailable VM networking will not be impacted.This problem does not effect the v Sphere Host VMKernel Ports used for management, as the data for those is stored in the ESXi state, in a file called As it turns out though this problem will only manifest or be visible if v Center is unavailable (but is not caused by v Center).A little while ago Duncan Epping posted a great article titled Distributed v Switches and v Center Outage What’s the Deal, which generated some good debate.