Hard disk failures seem to have a way of occurring when no current backup is available. Because of this, the Internet is chocked full of information about various methods of recovering data after a hard disk failure occurs. What you might not realize, is that the corrective action that you take has the potential to result in rendering your data unrecoverable, or causing, even more, data to be lost. Consequently, if you do find yourself trying to recover data from the failed hard disk, then it is clearly in your best interest to adhere to established best practices for data recovery.
Minimize Access to the Drive
The first rule of recovering data from a failed hard drive is to minimize access to the drive. If the failure occurred as a result of a mechanical problem, a faulty data cable, or a bad disk controller, then repeated access could potentially cause you to lose even more data. At least, some degree of corruption has already occurred, and you don’t want that corruption to spread to data that has so far been unaffected by the failure.
The best practices for data recovery is to minimize the chance that the corruption will spread is to avoid booting off of the failed drive. Remember, the boot process typically consists of thousands of individual read and write operations. Depending upon what is wrong with the drive, any one of these operations has the potential to cause further damage. Your best option is to contact a data recovery service (The Data Rescue Center).
Don’t Install Anything
By far the most common mistake that is made in data recovery situations is that of installing software onto the failed drive. If, for example, the operating system fails to boot then it might be tempting to reinstall the operating system. Although reinstalling the operating system might allow you to boot once again the system, there is a good chance that you will overwrite some otherwise recoverable data in the process, thereby making the data loss permanent.
Similarly, you shouldn’t install any data recovery tool onto a failed hard disk. At first, this one seems counterintuitive. After all, if you want to use a data recovery tool, that tool is going to have to be installed somewhere. The problem is that if you install the tool onto the failed hard disk, then you risk overwriting data that you might otherwise be able to recover. There’s nothing wrong with running a data recovery tool, but the tool needs to be run from somewhere other than the failed hard disk.
Don’t Attempt an in Place Repair
Another common mistake that is made during data recovery operations is that of attempting an in-place repair. For example, the owner of a Windows system might run CHKDSK on a failed hard disk in an effort to correct the problem. The problem with using CHKDSK or other tools to try to remedy a failed hard disk is that such tools perform write operations. If a data recovery tool attempts a recovery operation directly on a failed hard disk than the tool is making modifications to potentially recoverable data. Ideally, these modifications will allow the data to be recovered, but you have to consider what happens if something goes wrong. If the data is reassembled incorrectly, or if the recovery operation encounters a mechanical failure, then the data will likely be rendered unrecoverable.
Boot from External Media
If you are attempting a recovery operation on a failed hard disk, then it is extremely important to boot the system from some removable media such as a USB flash drive or an external hard disk. Doing so not only reduces wear and tear on the drive, but it also reduces the chance of the corruption spreading. What if the data corruption was caused by malware? Booting from an infected hard disk could result in even more data being damaged. Even if malware is not to blame, it can be difficult to recover data with the computer’s operating system running. The operating system may hide or lock some of the files that you are trying to recover.
Move Good Data to a Safe Place
Let’s suppose that you are able to recover some data from the failed hard disk. Because the hard disk has already failed once, the disk should be considered to be untrustworthy. As such, you should not risk storing your data on a disk that could fail again at any time. Any data that you manage to recover should be moved to a safe location (a different disk) immediately.
Create a Backup
When all is said and done, the best practices for data recovery is to be sure you always back up any data that you have managed to recover. Remember, the lack of a good backup is what made the data recover operation necessary in the first place.