Recovering Lost Data From a Hard Drives
Overview
Modern computer system hard disk drives can contain a massive amount of data. So when your hard disk drive fails, and there are no recent backups available, data recovery is the only option available.
Introduction
A hard disk drive consists of a number of component parts. Each of which has its own failure modes.
1. Electronics
2. Mechanics
3. Firmware
4. Logical
Electronics
The electronics on a hard disk is the ‘brain’ of the hard disk drive and a single component failure will render the drive useless. Data recovery from hard disks with electronics failures requires highly skilled electronics engineers who can to make temporary repairs in order to recover the data.
There are also electronic parts inside the hard disk drive that are critical for the correct operation of the hard disk drive and consists of the head pre-amplifier circuit.
Mechanical
The critical mechanical parts of a hard disk drive comprise of, the actuator arm, the motor and the platters. (There are other Mechanical parts, vibro-acoustic components, filters, VCM Magnets, etc, but these are less critical).
The majority of mechanical failures involve the Head pre-amplifier. Whilst this is not exactly a mechanical failure, the method that the head pre-amplifier is attached to the head stack means that when it fails it involves the replacement of the entire head stack assembly.
The next biggest cause of failure is motor failure. This is probably the most serious problem and requires specialist equipment so that platter alignment is not lost when removing and replacing the motor. Main problems with motors are burnt out coils and seized bearings.
Firmware
The firmware area or System Area (SA) is a section on the hard disk drive that contains the manufacturer’s proprietary information such as
- Operational code
- Translator Tables
- Head maps
- Self test logs
- Security Data
- SMART Logs
- Zone Tables
- Grown Defect Maps
and many others
For a hard disk drive to run properly it is vital that the Firmware Zone is error free. Fixing the Firmware on a hard disk drive is a highly skilled job and requires specialist equipment. Making a mistake when modifying the information in the Firmware of a hard disk can render a drive useless.
Logical
Logical problems are where there is no physical problem with the hard disk drive and it is fully functional. Logical problems are where data has become inaccessible for some reason, for example, the user has deleted the files, the computer has come under virus attack. The skill set of the engineer requires knowledge of how the operating system that the data was stored on works. Also, knowledge of the structure of individual file types so that quality of files can be determined on a bulk and individual basis.
Recovering Data from Hard Disks
MjM Data Recovery Ltd