Dealing with data Loss from a hard disk data recovery:

Data loss is one of life’s inconsistencies you must be prepared for. If your system suddenly fails on you and without your adequate data back up, data recovery is your only option. Data recovery can be done from botched hard disks, storage devices and systems. It can be affected from laptop, desktop, RAIDs and other systems running Windows, Unix, Linux and Macintosh.

Hard disks store electronic data on layered hard disk platters’ magnetic surfaces. Hard disks use magnetic recording techniques. This magnetic medium can be easily erased and rewritten. Data is stored onto the disk in the form of files, which are a named collection of bytes. The bytes can be:

1. ASCII codes for the characters of a text file;

2. Instructions of a software application for the computer to execute;

3. Records of a database;

4. Pixel colours for a GIF image The file will always be a string of bytes.

The hard disk recovers bytes when a program running on the system requests a file and sends them to the CPU one at a time. Hard drive data loss falls generally into two categories: Logical failure – Some files or data are inaccessible even when the hard drive is in working order for logical causes such as an accidental reformatting or lost partition. Logical locations where data files are stored relate to a number of physical locations on the surface of the hard disk platters. Incorrect upgrade applications, OS (operating system) errors or reloads that corrupt tables which hold these logical locations, rendering data to be inaccessible are the reasons for a logical failure.

The common Microsoft Windows recovery procedures for logical failures are:

1. Data retrieval and restoration from repartitioned HDD

2. Data recovery of data lost after a Format or Fdisk

3. Imaged or ghosted hard disk drives’ data recovery

4. Data from HDD relating to Chkdsk and Scandisk Mechanical failure - The most common causes are head crashes and motor failures, which result in the Hard disk not functioning.

The most common disk failure is "Head Crash" – heads are placed micrometers from the disk platters. When the internal read and write head of a device touches a platter it grinds away the magnetic surface. Causes of Hard Drive Failure include: Power surges or voltage fluctuations often heat or poor manage the system that results in electronic component failures. Substitution, repair, specialist re-programming and calibration are the solutions for Data recovery.

Motor Failure: Fluid bearings in the hard disk motor spindles may leak, become overheated and finally in-effective resulting in the failure of the hard disk platters to rotate. Relocation of platter and components to another assembly of hard disks is the only way during the process of repair and Data recovery. Malfunction of the read/write process, bad data read/write cycles and finally read/write head failures are also culprits. Media Damages are imperfections during normal operations that may increase due to vibration, shock, heat and other reasons. Here the operating system will either fail to boot and data files or flag errors such that data becomes inaccessible.

Data recovery options include read/write head replacement and file repair. Firmware Corruption: At times the firmware will “roll back” or become corrupt to an incorrect set of factors due to software bugs and viruses, overwriting, physical damages, natural disasters, control bus protocol failure, etc. This results in the location of the stored data as reported to the operating system to be lost. The hard disk will function properly by simple restoration of the correct parameters.

The process of recovering trapped data from the damaged hard disk device when it cannot be accessed in normal conditions is called Data recovery. Hard disk replacement is a common solution. The disk drive can be opened and parts such as arms and chips, read/write heads, and the platters can be removed and placed into another drive. But, Data recovery is not limited to just replacing parts. Hard disk recoveries, necessitated due to mechanical failures, should be carried out in dust-free cleanroom environments where they will have to be cautiously dismounted, inspected and processed. Hard drives are imaged. A copy of the disk is made and transferred to a new system.

Data recovery procedures also “force” the drive to read around the bad area to extract the maximum recoverable data possible. Data recovery is a specialised task and it is best entrusted to recovery professionals