We need to be able to install Hops over existing Hortonworks/Cloudera installations.
One alternative would be to shut down their NameNode(s), import the FSImage and EditLog to NDB and start HopsFS as the new NameNode. Same goes for DataNodes.
However, the approach Salman Niazi used to acquire the Spotify traces would be better. We run a seconday NameNode that pushes changes to NDB.