How Data Recovery Works: Explaining the Basics

By : Jon Wuebben
Data recovery. It's a reality for almost every single one of us. Everyone has had their desktop computer or laptop freeze, their system knocked out by a natural disaster or some other type of system crash. At some point in time everyone will suffer a hard drive crash.

The question is this: Was it backed up? According to a recent survey, only 12% to 15% of us backup our data on a weekly basis. With statistics like that, it's no wonder so many people are trying to get into the data recovery business!

In terms of the data, most people assume it's gone forever. It's easy to understand why that fear persists; most of us start encountering problems when our data is no longer in our files or trashcan anymore. Let's face it: most people are not technically savvy. They don't know how to get the data back and more often than not - do more damage trying.

When a file disappears, it's true that it doesn't appear anywhere visible. Where is it then? It's most likely on the hard drive. Why can't we see it anymore? Because what's been erased is the computers "pointer" that indicates the location of that page, not the page itself.

Eventually, the hard drive will write new data over the area where the old file is located. What's the function of the pointer? The pointer is used by the operating system to create the directory tree structure. When the pointer file is erased, the actual file is invisible to the operating system. In reality, it is still there until the file system reuses the space. The pointer is kind of like the table of contents in a book: tear it out and you're not sure what's inside. Of course, this scenario only applies to a hard drive that has not suffered a mechanical failure.

So data recovery is an easy process, right? Just locate the pointer, and Presto - it's all done. Wrong! Actually, it can be a very difficult and expensive undertaking. Finding the original table of contents which shows where the files actually exist can sometimes be a simple task, however this isn't typical. Data recovery companies work on fixing the problem in a number of ways.

If it's easy, they simply rebuild the file system structure and save those lost files from being overwritten. On the other hand, the drive may have suffered a physical failure such as a circuit board failure, service track failure or head crash. In this case, the drive may need to go into a clean room.

In some cases, engineers discover the cause of the file system error and then systematically fix the file system, which requires it to be repaired by hand in some cases. They then repair the internal structure of data files if necessary. Corrupt data that is specific to individual programs can also be repaired using file repair software utilities for Word, Excel, PowerPoint, Access, Outlook, and also database recoveries on Microsoft Exchange server and Microsoft SQL server.

If it's a basic problem, data recovery may simply entail running data recovery software on the drive. If the hard drive has not physically failed, most computer stores or IT managers can perform this task. Some people go out and purchase data recovery software, set up a website and claim to be a data recovery company. Beware of these companies!

So what are the steps involved in data recovery? First, is the diagnosis, which determines if the hard drive is functioning and what method of recovery may be attempted. Depending on the problem, a good data recovery lab will have many different ways to attempt a recovery. No one method works all the time.

If it is a "software only" recovery, then the recovery technician can produce a file listing showing all the files that can be recovered. The smart data recovery engineer will usually work on a copy of the client's drive. This way the client's drive is not altered in any way.

If the drive needs to be looked at in the clean room, then this is the next step. The clean room is an ultra-clean environment used when working with microscopic computer components. In many cases the electronics on the disk drive fails and it needs to be either repaired or replaced.

Once the drive is repaired, then the file structure fix can proceed. The file structure is a complete file listing that shows all of the files and directories on the volume. The last step is the recovery phase, which copies out and backs up the data to CD's, DVD's or another hard disk drive.

Hard disk drives are very sophisticated hardware. Working with software devices and data recovery should only be attempted by a professional data recovery service.


Author Resource:- ITS - Data Recovery has been providing professional data recovery, data repair, computer forensics and evidence recovery services and software since 1980. Located in Los Angeles and serving clients around the world. For inquiries, contact http://www.datarecoveryspecialist.com/ or (818) 727-1500