Manage Old Data

When there are changes in how data is stored on disk, Jenkins uses the following strategy: data is migrated to the new structure when it is loaded, but items/records are not resaved in the new format. This allows for downgrading Jenkins if necessary. However, it can also leave data on disk in the old format indefinitely. The table below lists items/records containing such data, and the Jenkins version(s) where the data structure was changed.

Sometimes errors occur while reading data (if a plugin adds some data and that plugin is later disabled, if migration code is not written for structure changes, or if Jenkins is downgraded after it has already written data not readable by the older version). These errors are logged, but the unreadable data is then skipped over, allowing Jenkins to start up and function properly.

Type	Name	Version	Error

No old data was found.