Andrew Whitehead is a contributor at Free-backup.info — the home of the popular Amazon S3 based online backup service — Back2zip. This article available at http://free-backup.info/how-is-a-hard-drive-recovery-done.html
How a Hard Drive Recovery is Done
When your hard drive is ruined, the obvious question to ask is, “how do you get my data back? ” Despite what data recovery businesses may tell you, it is not done by black magic nor is it anything approaching rocket science, it has more to do with having the right equipment, and enough knowledge to know what to do with it.
Logical Hard Drive Recovery
Generally speaking, the first thing a hard drive recovery business will do when they receive a hard drive is to evaluate it to determine what recovery method will be required.
If the drive failure is a software problem, they will perform a scan of the drive to try and repair the file system. In some cases a partition can be repaired, restoring the hard drive to its status prior to the drive failure. If this cannot be done, they will do a very low-level scan, searching every sector of the hard drive for files. Once they have located a lost file, it will be copied onto the media of your choice, this is usually a CD-ROM, a DVD-ROM, or ideally onto another hard drive.
This type of Logical hard drive recovery takes a great deal of time, particularly if the hard drive is close to physical failure. It is not unusual for scanning to take a whole day, and recovering any files that are found to take another.
Physical Hard Drive Recovery
If your hard drive is suffering from a physical failure, the recovery method is considerably more difficult. There are two discrete forms of physical failure; electronic and mechanical.
When recovering data after a physical failure, a major hurdle is getting the correct parts to get the drive going again. A problem with hard drives is that if you have, for example, a 60GB Maxtor Hard Drive you will need another, identical, 60GB Maxtor Hard Drive to salvage parts from.
If it is the printed circuit board that has failed on your hard drive an identical circuit board is required to retrieve the necessary circuit components for replacement, because in most case it is not possible to swap the damaged circuit with the new one. Repairs of this nature require good soldering skills and a thorough knowledge of electronics to be successful.
Hard Drive Recovery Environment
You will see “Class 100 Clean Room” in a lot of advertising by hard drive recovery professionals. A Class 100 Clean Room maintains an air purity of less than 100 airborne particles over 0.5 microns in diameter in each cubic foot of air. This is to protect the sensitive internal components of hard drives. Whenever a hard drive is being worked on, a minimum of Class100 clean room should be used.
Hard Drive Recovery Time
The time taken for a hard drive recovery is usually 5-10 working days for a physical recovery (though if components are not readily available it may take weeks! ), 2-4 for a logical problem. An express service is often available, at a high price.
