Moving an RRDtool installation to a 64-bit machine
At work, we moved our internal graphing and dashboard web site to a new machine, from an old two-processor machine to an eight-core, 64-bit machine with striped and redundant drives. A super fast machine.
I was banging my head against a problem with the RRD scripts: they would fail to update the graphs properly, or even update the RRD files brought over from the old machine. It seemed like it must be some kind of error I made compiling the package, right?
Wrong. It turned out that RRD data files are not binary compatible from one architecture to another (in this case from 32-bit i368 to 64-bit x86_64.) When I deleted the old files, and rebuilt them from original data, everything worked fine.
Lesson: don't move your RRD data files and expect them to work. Recreate them from original sources (and make sure you keep your original sources!).