Hi, pdump is not supported on any recent OVS.

See commits,
https://github.com/openvswitch/ovs/commit/4cf89cb0742419cda7b290816fbf3b9f6edfa1fc
and
https://github.com/openvswitch/ovs/commit/4ae8c4617fd34422ac7edabe4d63a78c6442dbd5

It would be better to go to
https://mail.openvswitch.org/mailman/listinfo/ovs-discuss for questions on OVS.