On Wed, Apr 04, 2007 at 09:49:15PM +0200, Sebastian Henrich wrote: > At 17:39 04.04.2007, Jon LaBadie wrote: > >... > >> > >> I diabled the hardware compression before I used the tapes for > >the first time like it's described in the docs. mt shows me that > >hardware compression is off after inserting a tape. So I think that > >it's really disabled. > >> > > > >The switch may not occur unless the drive actually attempts to read the > >tape. > >Amanda does an initial read before any attempt to write to a tape to > >check if it > >is actually an amanda tape and is the expected amanda tape. > > I'll take a look at this later. > > >> > Amanda also tracks the amount of compression on a per dle > >basis, so if you > >> > know beforehand the ratio, you can put it in the dumptype spec > >section to > >> > give amanda a head start on a good guess. > >> > >> How can I put the ratio in the dumptype spec? > > > >Can't. The history of last 3 dumps at full and incremental levels is > >recorded > >in the curinfo file for the DLE after a dump. I wonder (don't know) > >if you could > >clear or edit that file or the relevant lines. > > > > $ grep comp <curinfo_dir>/<host>/_<DLE>/info > > full-comp: 0.386351 0.386012 0.385504 > > incr-comp: 0.196589 0.207102 0.197036 > > $ > > > >The DLE I ran this sample on shrink to about 38% and 20% of the original > >size > >for full and incremental dumps respectively. > > My curinfo files look like this: > > :full-comp: 1.403959 1.404711 1.404836 > :incr-comp: 1.953383 1.707214 1.944336 > :full-comp: 0.998471 0.998600 0.999358 > :incr-comp: 0.658643 0.633644 0.635077 > info:full-comp: 1.470862 1.470858 1.470862 > info:incr-comp: 1.920387 1.905384 1.905772 > info:full-comp: 1.048603 1.048608 1.048625 > info:incr-comp: 0.225497 0.260856 0.228623 > info:full-comp: 1.587112 1.587132 1.587116 > info:incr-comp: 0.025000 0.691057 0.681301 > info:full-comp: 1.264800 1.264797 1.264808 > info:incr-comp: > > I have a problem with interpreting these values because they're > bigger than 1. For example in the first lines. Does this mean that my > backup shrinked by 140 %? Or does it grow by the factor of 1.4? >
A guess only ... As I recall, your recent amdumps have encountered problems, probably for more than the last 3 recorded values. In such cases, the amount of data dumped would be very small. Yet if amanda tries to save it to tape, it must write a 32KB block. In that case expansion may seem to have occured and been recorded. -- Jon H. LaBadie [EMAIL PROTECTED] JG Computing 4455 Province Line Road (609) 252-0159 Princeton, NJ 08540-4322 (609) 683-7220 (fax)
