This makes perfect sense, and I grabbed the old ClusterVmGroup, and used "add" as the array update option. Still getting a SOAP fault.

When I use "edit" with the existing ClusterVmGroup it still replaces all machines in the group with the one specified.

Here is the code that is producing the SOAP Fault:

                my $groupSpec = new ClusterGroupSpec();

                $groupSpec->{operation} = new ArrayUpdateOperation("add");

                $groupSpec->{info} = $ClusterVmGroupView; #this is ONLY the ClusterVmGroup I'm editing (retrieved using configurationEx->group)

                $groupSpec->{info}->{vm} = [$vm_view];

                my $spec = new ClusterConfigSpecEx();

                $spec->{groupSpec} = [$groupSpec];

                $cluster_view->ReconfigureComputeResource(spec => $spec, modify => 1);

And the error:

SOAP Fault:

-----------

Fault string: A specified parameter was not correct.

Fault detail: InvalidArgument