On Wed, Apr 04, 2007 at 11:01:20AM +0200, Sebastian Henrich wrote: > > On Tuesday 03 April 2007, Sebastian Henrich wrote: > > >Hello, > > > > > >I'm using amanda 2.4.5 to backup my server. The tape is a HP DAT 72. > > >This drives stores 36 GB of uncompressed data. I switched the > > >hardware compression off and tried to use the software compression. > > >Now I have the problem that amanda tells me every time > > > > > You may be getting bit by something I ran into several years ago now. > > > > If the tape is written with the hardware compression on, then the drive > > will detect that and turn the compression on even if you think its turned > > off. ... > > 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. > > 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. -- Jon H. LaBadie [EMAIL PROTECTED] JG Computing 4455 Province Line Road (609) 252-0159 Princeton, NJ 08540-4322 (609) 683-7220 (fax)