Best practices to recover data from faulty hard disk

Introduction

Laymen explanation

If anytime you experienced disk failure, you must have understood the pain of loss of data.You mught be regretting why you are not keeping regular back-up. However for day to day home usage, rarely anyone is using technology to backup data automatically. There are online services for this, but still user doesn't enable it for all of his data. So, it is practical to think that situation may arise when we need to rely on data recovery from the faulty hard-disk. This article helps in this requirement.

Technical explanation

Just running a recovery tool is not the answer since data may get more damaged during this attempt.

The job of a technician tasked with recovering data from a heavily damaged disk is similar to that of a restoration expert working on an antique or historical document. The goal is to recover as much valuable information as possible while keeping the original source material intact. Likewise, data recovery technicians and antique restoration professionals share a best practice for achieving this objective: handle the delicate object as little as possible.

When your hard drive becomes corrupted or physically damaged, every action you perform on it can cause the loss of more data.

Best practice

First step when attempting to recover data from a damaged disk is to clone the disk. Then, you would perform your intensive data recovery operations on the disk image, rather than the original disk. This has a number of benefits. First and foremost, you don’t cause any further damage to the original hard disk. Cloning a disk performs damage control, putting an end to any further degradation or loss of data. Secondly, reading from a disk image is much faster than attempting to read from a faulty hard disk drive. Your computer will stumble when it encounters a bad sector on a hard disk drive. It’ll attempt to read and re-read the sector multiple times before declaring it damaged and then moving on. Not only can this cause further damage to the drive, but depending on the size of your drive and the extent of the damage, it could take hours to go through the whole disk in this fashion.

Linux tools

dd command

Disk cloning is the process of copying the contents of one computer hard disk to another disk or to an "image" file.

Linux dd command can be used for the same.

fsck command

fsck is used to check and optionally repair one or more Linux file systems.

Reference

http://www.r-studio.com/Clone_Disks_Before_File_Recovery.shtml

https://sites.google.com/site/jbsakabffoi12449ujkn/home/linux-tools/useful-linux-commands-and-apis