Optimize Upgrade Performance
Review the following recommendations to speed up the upgrade process. The suggestions below reduce the amount of content to move and free up resources to avoid issues that arise in old repositories.
Disable system feeds System feeds were used for team communication and are not supported in Nexus Repository 3. Disable system feeds if they are not in use.
Remove the repair index tasks These tasks support searching components but are not needed while using the Upgrade Wizard. Consider disabling them repositories to improve the server performance.
Update Repositories Index
See the KB article on the repair Index tasks.
Snapshot Removal Tasks Run the following tasks to delete unneeded component versions and reduce the amount of content to move.
Remove Snapshots from Repository Remove Unused Snapshots From Repository
Deprecated Repositories Remove deprecated repositories and duplicate proxy repositories. Proxies pointing to sites that don't exist slow the upgrade as Nexus Repository 2 gets hung up trying to contact bad remotes.
See the KB article on removing codehaus.org.
Rebuild Maven Metadata Files Task Use this task to repair a corrupted Maven repository storage on disk. This may help with errors during the upgrade.
Staging Rules Redefine or reduce the number of staging rules and profiles.
Scheduled Tasks for Releases When empty Use Index checkboxes are under the Task Settings, remove those specific tasks.