Delete broken datasets from RRD file

Sometimes arises the wish to delete some broken datasets from RRD files. This is not possible with the out-of-the-box by design. But there are the rrdtool dump/restore commands. The interchange format is XML. So the idea is to modify the XML before restoring it.

There are two small deficiencies with the XML:

• It's not documented and
• some useful information is provided by XML comments instead of be part of the XML itself.

This makes XSLT a little bit processing difficult. But here is a Gist including some XSLT transformations, that are trying to handle the deletion of some datasets and producing a new working RRD file. (tested against rrdtool-1.4.7)