I wanted to make a disk clone for backup purposes of a Windows7 HDD for an HP laptop. This was for extra safety before restoring the Laptop to factory defaults. I tried Clonezilla but for some reason it failed to even begin the cloning process ( I did not take note of the errors). I resorted to using dd from the Terminal.

I was booting Ubuntu from an external USB HDD and I was trying to create my backup in a partition on a different HDD also connected via USB. The partition was bigger than the disk I was trying to clone. So fifteen hours later I found that the destination partition was corrupt and my back-up files were nowhere to be found. Well I couldn't face another 15 hours of dd with an unknown outcome so I took a gamble and was able to restore the Windows machine to its factory condition using HP's built in restore program.

So there was no harm done.

When I was waiting for dd to complete I did a few things that may or may not have caused the procedure to fail:
1 - I mounted the target partition part way through dd procedure to see if any files had shown up - they had not.
2 - I kept an eye on the process by running the command: $ sudo kill -USR1 [dd PID] which caused dd to print out a progress report before it would carry on.
3 - The command used to run dd was: sudo dd if=/dev/sda of=/dev/sdc2 (note - sda is a Windows HDD with three partition, sdc2 is the second partition on an HDD with two partitions)

One other thing may have caused a problem and this was reported by fdisk -l in a terminal: There was a warning that "Partition (sdc1) does not end on cylinder boundary"

Does anyone know if one of the above could have caused the target partition to become corrupted after the dd procedure?
(It is marked as RAW - unformatted whereas before dd it was formatted for NTFS )