6

I have a drive in our iMac that has bad blocks, as booting from an Ubuntu 11.10 live CD and using ddrescue -f /dev/sda /dev/null finds them. I'd like to get the drive to remap them by writing to the blocks, say using hdparm --write-sector, but I don't want to do this without knowing what's in those blocks and finding the file that owns them, so I can restore the file from another source.

I found fileXray but don't feel like spending $79 to map a block to a file and hfsdebug has been taken offline. Are there suggestions on a tool or technique to use?

I looked at all the Ubuntu HFS+ packages to see if they could provide this info but nothing jumped out at me.

BTW, I used Disk Utility to erase the empty space, but it didn't get any of the bad blocks to be remapped, according to smartctl -A.

1
  • Back it up with Time Machine, erase the disk, and reinstall.
    – gadgetmo
    Feb 16, 2012 at 9:03

1 Answer 1

2

If you are running Lion, man fsck_hfs and look at the -B option which says it will print files given a list of block numbers. Note: I had to include -n -f on the command to force a check, otherwise it just reported *** NO MATCH *** for all the blocks in my list.

Also, before attempting to overwrite a block, I'd want to develop and run some test to verify the mapping is correct between block numbers reported by ddrescue and those used by fsck_hfs and hdparm.

1
  • 1
    Passing -l to fsck_hfs seems like a safer way if the filesystem is currently mounted. Oct 18, 2012 at 23:08

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.