File: ddrescue.info,  Node: Ddrescuelog,  Next: Invoking ddrescuelog,  Prev: Generate mode,  Up: Top

15 Ddrescuelog
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Ddrescuelog is a tool that manipulates ddrescue mapfiles, shows mapfile
contents, converts mapfiles to/from other formats, compares mapfiles, tests
rescue status, and can delete a mapfile if the rescue is done. Ddrescuelog
operations can be restricted to one or several parts of the mapfile if the
domain setting options are used.

   When performing logic operations (AND, OR, XOR) on mapfiles of different
extension, only the blocks present in both files are processed. Other blocks
are left untouched.

   Here are some examples of how to use ddrescuelog, alone or in combination
with other tools.


Example 1: Delete the mapfile if the rescue is finished (all data have been
recovered without errors left).

     ddrescue -f /dev/sda /dev/sdb mapfile
     ddrescuelog -d mapfile


Example 2: Rescue two ext2 partitions in '/dev/sda' to '/dev/sdb' and
repair the file systems using badblock lists generated with ddrescuelog.
File system block size is 4096.
Note: you do need to partition '/dev/sdb' beforehand.

     fdisk /dev/sdb                                   # partition /dev/sdb
     ddrescue -f /dev/sda1 /dev/sdb1 mapfile1
     ddrescue -f /dev/sda2 /dev/sdb2 mapfile2
     ddrescuelog -l- -b4096 mapfile1 > badblocks1
     ddrescuelog -l- -b4096 mapfile2 > badblocks2
     e2fsck -v -f -L badblocks1 /dev/sdb1
     e2fsck -v -f -L badblocks2 /dev/sdb2


Example 3: Rescue a whole disc with two ext2 partitions in '/dev/sda' to
'/dev/sdb' and repair the file systems using badblock lists generated with
ddrescuelog. Disc sector size is 512, file system block size is 4096.
Arguments to options '-i' and '-s' are the starting positions and sizes of
the partitions being rescued.
Note: you don't need to partition '/dev/sdb' beforehand, but if the
partition table on '/dev/sda' is damaged, you'll need to recreate it
somehow on '/dev/sdb'.

     ddrescue -f /dev/sda /dev/sdb mapfile
     fdisk /dev/sdb                                  # get partition sizes
     ddrescuelog -l- -b512 -i63s -o0 -s767457s -b4096 mapfile > badblocks1
     ddrescuelog -l- -b512 -i767520s -o0 -s96520s -b4096 mapfile > badblocks2
     e2fsck -v -f -L badblocks1 /dev/sdb1
     e2fsck -v -f -L badblocks2 /dev/sdb2