Differentiating Logical and Physical Storage Media Damage

Data Recovery is an act of salvaging lost data from a physically or logically crashed storage media when it cannot be normally accessed. Though most of the lost data is not permanently lost-simply inaccessible, but the recovery solutions and techniques are entirely dependent upon the nature of data loss, logical or physical. That's why it becomes essential to differentiate between these two types of damages that might prevent the storage media to be inaccessible by the host system.

Logical Damage

Among other reasons like accidental file deletion and operating system crash, most of the logical damages root from file system inconsistencies. The file system might become dirty that might compel its structure not to completely write the information to the storage media. Some factors that can cause this corruption are:

Power outage
Faulty hardware like RAID controller
System crash
Drivers issues

A file system in such a inconsistent state behaves abruptly and shows symptoms like:

Drive reports incorrect information about free and occupied space
Cross-linked files
System crashes
Unbootable system
Loss of files

Most of the file system problems can be fixed by their repair utilities like Disk Utility in Mac, CHKDSK in Windows and FSCK in Linux. But if the data is completely inaccessible, you need to use data recovery tools that prove to be powerful recovery applications for recovering and restoring lost information, provided data has not been overwritten.

Physical Damage

A storage media might get physically failed due to mechanical reasons like head crash, media breakdown, motor failure etc. and also because of water, fire and heat like factors. A physical wear and tear is also one of the prominent causes responsible for such crashes. Such events can fetch permanent data loss as well in situations when metallic substrate or dye layer of the media gets scratched off. Typical symptoms indicating physical media failure are:

Unexpected clicking sounds from media
Hard drive stops spinning
BIOS fails to recognize the media

Due to the complexity factor involved in the process, physical media damages should not be handled by end users. The data recovery process requires opening the media in safe surroundings of Clean Rooms and applying certain component level procedures to repair or replace the damaged internals. Also, the software processes like disk imaging and using recovery software are also included.