Hard Drive Recovery Techniques, Solutions, Procedures and Tools

Written By Sam on 27 September 2009

Data Recovery is the process of getting back data from damaged, failed, corrupted or inaccessible secondary storage media such as hard disk drives, storage tapes, CDs, DVDs, RAID etc. Many of them would do a backup of data at regular intervals to avoid last minute surprises. Though you do a backup at regular intervals you might still have some important data on the corrupted disk. Recovery can be required due to the physical damage to the storage device or logical damage to the file system. Recovering data from logically damaged disk can be done easily when compared with the physical damage of the disk.


We have already covered many posts related to recovering data like which you can checkout – Backup and Recover Your Data With GFI Backup 2009 Home Edition, Recover Data From Disks With Bad Sectors and Scratches Using Unstoppable Copier, Recover Deleted Files in Windows 7 With Recuva Freeware File Recovery Tool and Recover Deleted From Files Memory Cards & Hard Disk With DiskDigger.

Recovering Data After Physical Damage: Physical damages cause loss of data and in many cases the logical structures of the file system is damaged. This causes the logical damage which must be dealt before any file being recovered from the failed media. But most physical damages cannot be repaired by end users. Costly data recovery companies are often employed to get back the important data. Recently one of my friend had this issue and he contacted DTI Data who offers free upfront flat rate price quotes on all Hard Drive Recovery.

Recovering Data After Logical Damage: Logical damage is primarily caused by power outages which prevents file system structures from being completely written to the storage medium. The result of the file system is in an inconsistent state which can cause many problems like strange behavior, system crashes or actual loss of data. Some kinds of logical damage can be mistakenly attributed to physical damage.

Recovery Techniques: Multiple techniques are involved in recovering data from physically damaged hardware. Some damage could be repaired by replacing parts in the hard disk which alone will make the disk usable but still there could be logical damage. Every readable bit from the surface can be recovered by a specialized disk imaging procedure. After acquiring the image, it is safely analyzed for logical damage and original file system can be reconstructed.

Hardware Repair: Hardware repair is like physical recovery procedure, procedures like removing a damaged PCB, and replacing it. Some data recovery companies have procedures which are highly technical in nature and are not recommended for an untrained individual. These type of harddrive repair procedures should be handled by experienced data recovery Engineers only.

Disk Imaging: After any logical damage has been repaired, the extracted raw image can be used for reconstruction of usable data. Once this is complete then the files may be in usable form although recovery is often incomplete. Tools like DCFLdd or DOS tools such as HDClone can recover data from all physically damaged sectors.

Preventing Logical Damage: The use of file systems like NTFS 5.0, ext3 and XFS will likely reduce the incidence of logical damage. These files systems can be rolled back to consistent state which protects data both against the bugs in the file system software and latent incompatibilities in the design of storage hardware. One solution is to use hardware which does not report data as written until it is actually written.

Recovery Techniques For Damaged Hard Disk


The two common techniques for recovering the data from logical damage are consistency checking and data carving.

Consistency Checking: This involves scanning the logical structure of the disk and checking to make sure the consistency with its specification. If the file system is sufficiently damaged then consistency check will fail completely. In this case the repair program may crash trying to deal with the mangled input. The problem can be avoided by installing the operating system on a separate partition from user data.

Data Carving: This is a data recovery technique which allows data with no file system allocation information to be extracted by identifying sectors and clusters belonging to the file. Data carving usually searches through raw sectors looking for specific desired files signatures. Data carving also known as file carving has traditionally required that the files recovered can be located in sequential sectors.

Recovering Overwritten Data: when the data is physically overwritten on a hard dick it is assumed that the previous data is no longer possible to recover. But Peter Gutmann a respected scientist says that this data can recovered through the use of Scanning transmission electron microscopy.

When you have really important data rather than trying out yourselves it would be better to consult an expert and take their help. There are many companies on the Internet which can help you to get back your data. DTI Data Recovery is one such company which I consulted when I was looking for RAID Data Recovery some time back. Although RAID systems increase speed and availability of data and are specifically structured to protect your data, a RAID system can even fail when conditions are bad.

2 Responses to “Hard Drive Recovery Techniques, Solutions, Procedures and Tools”

  1. abdullah_mh says:

    i unfortunately deleted a drive from my system and i lost so much of pictures could i retrieve all dat pictures pls help me soon

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