Last weekend we did some disaster testing for our datacenters. As this environment is not your usual metro cluster datacenter, there was need for some serious testing and one of the scenarios was taking the power away from the storage arrays.

All test went well and after some time everything was back online and looking good. But when we started the functional test, there were lots of network connectivity issues. After a little investigation we saw that some VM’s had their network card not connected anymore.

And when we tried to check and save it, VMware gave the following error:

Invalid configuration for device '0'

This problem occurs when your virtual network card is connected to a Distributed vSwitch and for some reason the configuration file of that virtual network card is removed from the datastore. The configuration of the dvSwitch is stored in different locations and the network card configuration is stored on the datastore on which the vm resides. For more information on the .vdsDATA folder you can read this blog and that blog.

Luckily this problem is fairly easy to solve. Just edit the settings of the troubled vm, select the network card, choose a different portgroup and save. Now open the settings again, select the old/correct portgroup, check the connected checkbox and save the configuration.

VMware KB2014469