Upgrade from Nexus Repository 2
Nexus Repository 3 is a complete redesign that does not include legacy code from Nexus Repository 2. Nexus Repository 3 uses a different storage model for managing components that is far more scalable for non-Maven ecosystems and deployment environments.
While this avoids file system limitations from Nexus Repository 2, it does require a more involved migration process to move to Nexus Repository 3.
The upgrade to Nexus Repository 3 requires creating an upgrade plan:
Review the Feature Equivalency Matrix
Begin with Determine your Upgrade Path
Upgrade your Nexus Repository 2 Instance
Complete the Optimization Steps
Follow the prerequisites for your upgrade method