Many people are running into scenarios where knfs or another glusterfs server is already running and: a. exports from the new server dont show up in showmount or b. the exports show up but mount requests fail because the client sends the mount request to the old nfs servers, failing the requests. The trick is to perform getport requests to check whether the portmapper already has a registration for nfs and associated protocols.
Please update the status of this bug as its been more than 6months since its filed (bug id < 2000) Please resolve it with proper resolution if its not valid anymore. If its still valid and not critical, move it to 'enhancement' severity.
Closing. nobody is complaining without this feature.