On Thu, 18 Apr 2002 at 4:03pm, Tom Beer wrote > > The quickest way to increase your tape usage is to cut your dumpcycle. > > Using the same amount of tapes this gives you the two advantages of higher > > tape usage and greater redundancy. > > I thought, that the redundancy is provided through the dump levels, so > that amanda backs up only specific - needed - parts of the file system? > Therefore, if some crash occurs, I can dump back a level 0 and than restore > the latest level 1 and 2 and everything is fine, is it?
Yes, that's true. The redundancy I was referring to was having multiple level 0s on tape at any one point in time, which happens for *every* filesystem you have if tapecycle>2*runspercycle. This comes in handy if, e.g., your drive eats a tape during the night's backup. Having multiple level 0s on tape means that the munched tape doesn't contain your only level 0 (and thus your only hope of full recovery) of a particular filesystem. Having a higher tapecycle/runspercycle ratio also means that you are less likely to overwrite your last level 0 of a particular filesystem should filesystems start growing at an unanticipated (damn users) pace. -- Joshua Baker-LePain Department of Biomedical Engineering Duke University
