What Is Hard Drive Imaging?
Hard drive imaging is the process of duplicating the entire contents of one disk to another. The data that constitutes your files and folders is stored on your hard disk in millions of tiny sectors, some of these sectors contain data that when combined with data from other sectors become files. Other sectors contain data that has been deleted, and some sectors contain no data at all as they have not yet had data written to them. The imaging process will copy every single sector on the hard drive, from the first sector to the last, regardless of the sector’s contents. Hard drive imaging is an essential part of data recovery and forensic computer investigation.
Obviously the hard drive that is chosen to receive the image must be the same size or larger than the hard drive being imaged from, failure to ensure this will result in an incomplete image.
Hard Drive Imaging in Data Recovery
Data recovery is the process of retrieving data from (faulty) hard drives where the data is inaccessible. There are many reasons why data on a hard drive becomes inaccessible, it could be something simple like an accidental file deletion, but more often that not a problem has developed on the hard drive that prevents the data being read or the hard disk working. Imaging the data from a faulty hard drive is often the final step in the data recovery process and can not proceed until the hard drive has been mended and the fault rectified or a work around put in place. Learn more about the different types of hard drive failure here.
Hard Drive Imaging in Computer Forensics
A computer hard drive that is suspected of containing evidence must first be imaged. Imaging a suspect hard drive preserves it’s contents by duplicating it to another drive. A mathematical checksum for each drive is produced during the imaging process that can then be compared. A match ensures the the image is an exact 100% duplicate. The original hard drive must not be modified in any way: the image can then be worked on and investigated while the original hard drive can be locked away and stored as evidence. Investigating the image of the original hard drive also provides a useful safety net should the investigator accidentally modify the data whilst examining it. Learn more about Data Clinic’s Advanced Data Recovery services here.
Sometimes hard drives that are suspected of containing evidence have been damaged so that they can not be imaged, in these case a data recovery process is first performed on the hard drive to get it into a working state that then allows it to be imaged.