oracular (2) myrescue-bitmap2ppm.2.gz

NAME

       myrescue-bitmap2ppm - Visualisation of the block bitmap for myrescue

SYNOPSIS

       myrescue-bitmap2ppm bitmap-file width [ rows width ] ...

DESCRIPTION

       myrescue-stat  reads  a  block  bitmap  from  myrescue(1)  and  generates  a visualisation of each blocks
       condition.

       The image is written to stdout in PPM(5) format.  You  can  pipe  the  output  into  one  of  the  netpbm
       converters or into ImageMagick(1) to convert it to a more common format like PNG.

       Successfully  copied blocks are shown as green pixels. Yellow-green-ish pixels indicate blocks that could
       be copied, but it took unusually long, indicating that this area might  be  near-failing.  Yellow  blocks
       have  been  tried  once, but could not be read, red blocks could not be read on multiple attempts.  Black
       pixels indicate blocks that have not yet been handled.

       The pixels are arranged left-to right, with the first block in the upper left pixel.  The  width  of  the
       image must be specified on the command line - just  pick any value.

       In  case  of  partially  defective  discs you might start by having myrescue do a random jump-around scan
       (option -J) and continually check the visualized block bitmap. If you are lucky, you might begin  to  see
       some  structure  in the image. If these structures somehow run diagonally, you can adjust the width until
       you get vertical stripes of defective areas. What this means depends on the internal layout of the  disc,
       but it could be defective heads, platters, sectors, cracks, a factory workers hair, ...

       Usually  internally discs have different zones, so after a few (hundred?) rows you might see the vertical
       structures bend off. To adjust the image, you can tell the tool to switch to a different  width  after  a
       certain number of rows. Repeat this until you identified all zones. The last width will be used up to the
       end of the bitmap.

       The resulting image will have the maximum width necessary to accommodate all zones.  Zones  with  shorter
       widths will be padded on the right with blue pixels.

       You  can  now  use this information to manually fine-tune the myrescue calls to concentrate on areas with
       higher probability of rescue.

AUTHORS

       Kristof Koehler <kristofk@users.sourceforge.net>

SEE ALSO

       myrescue(1), ppm(5), ImageMagick(1)

       http://myrescue.sourceforge.net/