This is a question that I have been asked more than once. Is it better to Scan or Clone a hard drive that needs data recovery? If you have a failing hard drive or a hard drive that might have some problems with it such as slow read access, I would recommend Cloning that drive to a good drive of equal size without any data on it. You can use the Clone tool in Data Rescue 3 to do this. The Clone Target (Destination Drive) will be erased and data from the source will be written to it. Because of this, it’s important that you make sure the drive you are cloning to does not have files on it that you need as they will be written over with the newly cloned data.
After the Clone finishes, you can scan the newly cloned drive to scavenge for the files you need. Since this clone is an exact copy of the original bad drive, this new clone will still not be bootable and will still have the same file structure damage/issues, but because it’s on a physically ok drive, the scanning will run better. This is only needed if you have a hard drive that is physically suffering somehow such as bad blocks or is running slow.
Running a scan on a drive with bad blocks or that is running slow might lock up the drive and prevent the data recovery process from completing. When scanning a cloned drive, the cloned drive is in better shape then the failing drive and can finish the scanning without the risk of drive failure.