I have a problem with drive cloning. Im using dd on damaged disk with bad sectors trying to make an image from it. Im booting computer with Live Linux CD .

Damaged disk: sda 146GB (NTFS) External drive: sdb 300GB (NTFS)

After running the command below im running out of space on disk sdb.

dd if=/dev/sda of=/media/sdb1/hdd.img bs=4096 conv=noerror,sync

The question is why im running out of space on disk sdb ?

UPDATE: There is 300 GB of free space on partition sdb1

  • To be clear, you do have 146G of space available on sdb, right?
    – nickgrim
    Sep 7, 2012 at 10:33
  • Yes, I have 300GB of free space on disk sdb
    – Alan Kuras
    Sep 7, 2012 at 11:21
  • It is okay, that your sdb drive has 300 GB capacity, but your sdb1 partition has also enough free space for that image file?
    – Eddie
    Sep 10, 2012 at 8:23
  • 1
    Can you add the output of df -h? Sep 10, 2012 at 8:28
  • Yes because there is only 1 partition on disk sdb (whole 300GB)
    – Alan Kuras
    Sep 10, 2012 at 8:46

2 Answers 2


/dev/sdb is a device special that represents the disk drive; it isn't a filesystem, but you've tried to use it as one.

Instead, try this:

dd if=/dev/sda of=/dev/sdb bs=4096 conv=noerror,sync
  • I dont want to clone drives one to one, i want to clone sda to image file (because sdb is USB disk drive). Im changing the question since it could be misunderstood.
    – Alan Kuras
    Sep 7, 2012 at 9:36

I'm not sure, but it looks to me like a problem in NTFS driver (problem with large files).

Did you mount the NTFS partition using ntfs-3g? Also, could you provide us with full dd output?

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