Myrescue 2

Myrescue is a program to rescue the still-readable data from a damaged harddisk. It is similiar in purpose to dd_rescue, but it tries to quickly get out of damaged areas to first handle the not yet damaged part of the disk and return later.

The program tries to copy the device blockwise to a file and keeps a table ("block bitmap") noting whether a block has been successfully copied, not yet handled or has had errors. This block bitmap can be used in successive runs to concentrate on the not yet rescued blocks.

The program has a special skip mode to handle read errors. Usually harddisk surface defects cover more than just one block and continuous reading in defect areas can damage the surface, the heads and (by permanent recalibration) the drive mechanics. If this happens, the chances of rescuing the remaining undamaged data drop dramatically. So in skip mode, myrescue tries to get out of damaged areas quickly by exponentially increasing the stepsize. The skipped blocks are marked as unhandled in the block bitmap and can be retried later.

Finally, the program has an option to multiply try to read a block before considering it damaged.