Barry Callahan wrote: > > Last week, I stumbled across a webpage that had a discussion on how big > to make your holding area, and I can't seem to find it anymore. I don't > remember where I saw it. >
The holding area should be at least as big as to be able to accomodate the largest amount of backup data that would fit on a real tape (not on estimated tape length). Taking the limit, a minimum holding disk area should have the capacity of exactly one tape (assuming runtapes to be 1, otherwise multiply by runtapes). Since you might have a tape library and the backups might fail on many consecutive runs, and/or you might be arbitrarily slow in flushing the contents of the holding disk to tape while failing images may keep coming into the holding area at the steady pace set by runspercycle, I postulate there is no upper limit to the capacity of the holding disk. A truly mathematical proof of this is left to the inclined reader ;-) > The example used on the page assumed 100GB in use, with 5% change per > day, and a dump every day in a 7 day cycle. The example came up with a > dump size of ~17GB. > > Does anyone know the page of which I speak, or of a similar discussion? > If so, would you be kind enough to post a link? > Try http://www.storagemountain.com/amanda-12.html http://www.storagemountain.com/amanda-17.html http://www.storagemountain.com/amanda-8.html -- Regards Chris Karakas http://www.karakas-online.de
