What is it?
Data recovery entails the process of retrieving and resurrecting lost, corrupted, damaged, or inaccessible data from internal or external hard drives (HDDs), solid-state drives (SSDs), USB flash drives, magnetic tapes, CDs, DVDs, RAID subsystems, and other electronic devices.
The 3 most common scenarios
The most common scenario involve an operating system failure, failure of storage device, or accidental deletion. In this case, the priority is to transfer the damaged data to another device.
The second scenario involves drive-level failure in which the data can not be easily read from other media devices. In this case, solutions include reparing logical file systems, updating firmware, to hardware replacement.
The third scenario involves the accidental deletion of data.
In this case, references to the deleted files in the directory structure are removed, but the deletes files are not yet removed from the physical drive. Therefore, the original file contents remain in a number of fragments that can be recoverable.
Physical vs Logical damage
Physical damage to storage media usually results from CD-ROMs’ metallic subtrate being scratched off, and hard disks experiencing several mechanical failures. The techniques utilized by many professional data recovery companies can usually rectify most of these physical damage as it is not the most severe form- asides from when the hard drive platters are damaged. Techniques used in recovering data from physical damage are u sally done professionally and not be end-users as it requires professional equipment.
Logical damage to storage media refers to a malfunction or problem in the hardware and requires software-level solutions. Damage to the partition table or file system can usually be retrieved using recovery software such as Testdisk. This type of data recovery can usually be performed by home-users without expertise in drive hardware.
Four phases of data recovery
Phase 1: Repair
Repair the hard disk drive so that it’s running
Phase 2: Transfer
Top priority of any data recovery is to transfer the data off the malfunctioned drie. Creating an image of the drive will ensure the safe storage of the data onto another functioning device.
Phase 3: Retrieve
Now that the data is safely stored on another device, it is suitable to attempt the retrieval of the lost data.
Phase 4: Rewrite
Most of the time, data damage needs to be reconstructed to become readable again. Using software methods or by manual reconstruction using a hex editor can resurrect corrupted documents.
