How to rescue data from a broken disk

If a disk is "only" throwing errors, but is not entirely dead yet, dd might help, but can cause a lot of grief. This recipe might help:

1. boot with GRML, use the forensic option
2. this might take a while, but this wait is worth while
3. mount a remote NFs share where you can write as root
4. in a screen environment use ddrescue, e.g. trying to rescue sda6: ddrescue -r5 /dev/sda6 /nfs/mount/file logfile
5. here logfile will keep track of the progress n case you need to CTRL-C the job

Afterwards you should have a disk image of that partition on the NFS server.

Word of caution! When trying to repair the file system of the image, first make another copy!

-- CarstenAulbert - 05 May 2010