The visual editing features of the RRD Editor allow users to modify the contents of an RRD (Round-Robin Database). Once an RRD is loaded into the editor, users can quickly locate a specific data point to modify or remove an entire Round-Robin Archive (RRA). The tool also allows new data sources and RRAs to be added in addition to detecting and removing spikes.
RRD Editor is licensed under the GNU GPL.
-  (thetoolsmith.com)