On Fri, Aug 27, 2010 at 2:41 PM, Chris Hoogendyk <[email protected]> wrote: > There was an exchange on the list in the last few months where I asked that > question and Dustin replied. He said that the historical algorithm had a > strong preference for an already written tape if one was available that > could be written to. I think he said that now that the new taper was out he > was thinking about implementing a more sane algorithm.
Wow, I'm cited twice as historical precedent! If you look closely at amanda-taperscan(7), you'll see that the unknown component of the algorithm that has changed in more recent versions is whether the changer is fast-searchable. In the past, only chg-zd-mtx+barcodes was searchable. Even chg-disk acted like a barcode-less changer, and just scanned slots in order to find a tape. The traditional algorithm will "stumble across" new tapes with a non-fast-searchable changer, but with a fast-searchable changer, it will always search for the oldest reusable tape, paying no attention to new tapes. It's unfortunate, but it's the way things have worked historically. Dustin -- Open Source Storage Engineer http://www.zmanda.com
