dd clone hard drive: Input/Output Error though "chkdsk" says OK

Question

I've used dd to clone hard drives before using 'dd' and a live cd, but have run into a problem.

The issue:

dd fails with an "Input/Output Error" on /dev/sda3 , even though windows "check disk" (chkdsk) says it's ok.

Context:

• Trying to replace my laptop hard drive w/ a faster one of the same size
• Laptop has NTFS on a 320gb hard drive
• Booting into knoppix
• Knoppix recognizes 'original' drive(/dev/sda)
• I am using a usb connection for ‘new' drive (irrelevant, but just an fyi)
• Knoppix recognizes the usb drive as /dev/sdb

• Using dd, as follows:

  dd if=/dev/sda of=/dev/sdb

• `dd gives the I/O error above at 82Gb (out of 320Gb)

• I then tried checking each partition as follows and found it failed on /dev/sda3:

  dd  if=/dev/sda1 of=/dev/null
  dd  if=/dev/sda2 of=/dev/null
  dd  if=/dev/sda3 of=/dev/null 
  

• I have ran windows xp chkdsk on the offending drive in both "find only" and "find and fix" mode and it reports no errors

Question

How can I find and fix the error on my original hard drive partition (i.e. /dev/sda3) so that dd reads it successfully?

Solution 1

Use ddrescue for that, it's able to read damaged disks.

And chkdsk probably won't find the issue because it only does basic checks of filesystem integrity; by default, it won't check all the partition space for read errors caused by damage.

Solution 2

I ran into the same problem and my OpenSUSE livecd didn't include ddrescue or Clonezilla. However, when I checked out the dd manual, I discovered that there was an option "conv=noerror" that allowed dd to continue past the I/O error.

dd conv=noerror if=/dev/sda of=/dev/sdc

Comments

[Petra]

The package for ddrescue is gddrescue on ubuntu if that's the livecd you're using. If you just do ddrescue you get dd_rescue which is a different older package.