* Dustin J. Mitchell <[email protected]> [20100820 13:00]: > On Thu, Aug 19, 2010 at 6:09 PM, Dustin J. Mitchell <[email protected]> wrote: > > There is a bit of taper/driver communication that should go on during > > that pause (REQUEST-NEW-TAPE/NEW-TAPE). That should be recorded in > > the amdump log. Can you attach that? > > I got this in private mail (the mailing list rejected it). Here are > the three key lines: > > driver: send-cmd time 9089.582 to taper: FILE-WRITE 03-00005 > /holddisk/down/20100818201101/gertrude._opt_amanda.0 gertrude > /opt/amanda 0 20100818201101 0 495980 > driver: result time 9089.585 from taper: REQUEST-NEW-TAPE 03-00005 > driver: send-cmd time 57627.988 to taper: NEW-TAPE > > So: (1) driver asks taper to write from holding, (2) taper asks for > permisson to use the new tape, and (3) driver says "sure!" -- > 48538.403 seconds later. > > You mentioned earlier that you are using flushing parameters. I was > thrown off the trail by your mention of timestamps. Now I see that > the flush parameters *are* relevant, as the driver is holding off on > granting permission to use the new volume until the parameters are > met. The time spent waiting for permission from the driver is counted > along with the time spent operating the changer in the final, reported > time. Arguably the bug is that the driver requests that the taper > begin a dump when the flush thresholds are not met - in fact, I > thought this was how the flush thresholds were implemented. The > actual implementation seems a very odd workaround. > > This is going to have to wait until Jean-Louis returns - he is the > only person on earth who understands the mental gymnastics that go > into those flush parameters. The driver is a maze of twisty little > passages, all alike, and I don't dare touch it (you should find this > shocking, given that I've been working full-time on Amanda for 4 > years!). > > I suppose we could fix the underlying reporting issue by simply > subtracting the time spent in the REQUEST-NEW-TAPE negotiation, but I > have the feeling there's a deeper bug here.
Thanks Dustin! Vacation!? Never heard of that ;) jf > > Dustin > > -- > Open Source Storage Engineer > http://www.zmanda.com
