Jean-Louis has been hard at work putting together support for multiple simultaneous writes to different tape devices. This means, for example, that if you have a changer with two tape drives, you can write different dumps to both of those drives at once.
Jean-Louis is on vacation at the moment, but in his absence he's asked me to discuss and test this new functionality out, so we can put it into the 3.2 release that should be out in a few months. The code is here: http://github.com/djmitche/amanda/tree/z11135 for those who can download it and try it out. The structure of this change is that the taper process now runs multiple scribes at the same time. Each scribe keeps track of one volume at a time, and takes care of spanning dumps from volume to volume. The driver specifies a scribe in every message it sends to the taper. So there is only one new configuration variable to control this: taper-parallel-write. It specifies the number of tapers that should be started at the beginning of amdump, and should be less than or equal to the number of drives you have. Even if you can't test this code out, I'm interested in feedback on the design, and what use-cases you see this meeting or not meeting. Dustin -- Open Source Storage Engineer http://www.zmanda.com
