Switching from other Persistence Provider

In order to switch the Persistence Provider to use, it is necessary to reset NiFi Registry. For example, to switch from FileSystemFlowPersistenceProvider to GitFlowPersistenceProvider, follow these steps:

1. Stop version control on all ProcessGroups in NiFi
2. Stop NiFi Registry
3. Move the H2 DB (specified as nifi.registry.db.directory in nifi-registry.properties) and Flow Storage Directory for FileSystemFlowPersistenceProvider directories somewhere for back up
4. Configure GitFlowPersistenceProvider provider in providers.xml
5. Start NiFi Registry
6. Recreate any buckets
7. Start version control on all ProcessGroups again