Have you ever seen a corrupted digital picture or were unable to open a file inside of an application due to data corruption? You are not alone. Data corruption is far more common than one might think. Since the beginning of the computer era, users have dealt with data corruption. Data corruption, in simple words, means that the data inside of a file has been altered from its original state.
It depends on the user assessment, if data or file corruption is a serious matter or not. If you work in a company that has thousands of files that are not usable anymore, then it might be a business-critical issue. Therefore, it is very important to immediately check your entire system after a corruption incident has occurred to determine the cause of the corruption and to solve the problem as quickly as possible.
The reasons for data corruption
The causes for corruption are various. In many cases, files can become corrupted when the storage device gets old. Several studies on the lifespan of traditional hard drives show that the failure rates in the last two years of the drive increase to its peak. The result of these “normal” wear-out related failures can be that during operation, or even when the drive is not in use, the stored data is altered from its original form. Files then become corrupted and can no longer be used. If this happens to pictures, the result can look like the picture created for this blog post.
Another likely reason for corruption can be a sudden loss of power. When files are saved onto a hard drive or a chip-based SSD and an unexpected power-outage takes place, only parts of a file may be transferred correctly, leaving the entire file corrupt.
This also happens to SSDs. When the controller in a SSD stops working or is not correctly communicating with the storage chips, the result is the same as if the power went down and transferred files became corrupted. Even if the corruption is not that serious and the file can still be opened, this doesn’t mean that all of the content is still correct. One possible and dangerous result is when, for example, an Excel sheet or a database is missing important figures and, in the end, the entire calculation turns out to be false.
While data corruption is nearly inevitable, data recovery is possible.
Think of two common types of files which could be corrupt: a Word (.docx) file and an image file like a .jpg or a .png file. In both cases, the user gets a message from their software application that the file is corrupt and cannot be read. What should the user do now?
To keep it simple, there are two different options to retrieve corrupted data: Using a data recovery software tool and getting help from a professional data recovery service provider.
There are some cases where the damage is not that severe and data recovery software can find fragmented parts of the file on other sectors of the disk and rebuild it.
However, DIY data recovery is always a risky business. Therefore, using data recovery software to get back the files can be hazardous when done incorrectly. Data recovery software should not be used on the original drive, but with an image or copy of the drive. By doing so, data recovery experts still have the chance to make a successful recovery. Otherwise, the attempts can cause more damage that can destroy the files for good. Files recovered by the software should also not be written back to the original volume until they have been opened and the contents of the file verified.
Data recovery engineers can do far more than even the best data recovery software can do. If there is an underlying hardware issue, they can often repair the damage and recover the underlying data or can repair the HDD or SSD to the point where they can fill in the missing or corrupted data. It is also possible for them to use data from spare blocks or parity to correct other types of damage.
Additionally, they may be able to use shadow copies or other fragments of data to rebuild corrupted files. It is also highly unlikely that a typical user is capable of determining if a corrupted file is recoverable or not. This is a job only an experienced expert can do.
So the question remains: What can a user do to get their corrupted file back without causing further damage to the files? Here are some tips:
First, don´t panic! Try to stay calm and carefully evaluate your options. If you experience data corruption, it is wise to act according to a plan that includes the following steps:
- Make a sector level image of the drive that contains the corrupted file(s). There are a lot of free tools on the market to do this. Attempt DIY recovery on the image instead of the original drive only! Set the original drive aside in case things don’t go well during your attempt to recover the data.
- After you have successfully recovered your corrupted data, you can try using a state-of-the-art file repair tool to fix, for example, a corrupted MS Office file. There are several products available on the market. Make sure that you choose a well-known and high-quality product for your specific case. Be sure to only use a tool like this on an image or copy of the drive. These tools are available for database files, videos or photos, but the outcome is not always perfect.
- If you attempt to fix the corrupted file, do not attempt to get the file back up and running again. Do not use the built-in OS volume repair tools to fix the disk (like CHKDSK or FSCK). Using built-in tools will often cause more damage and will render the data unrecoverable.
- If none of these steps work and you still need the data, contact a professional data recovery service provider.
Conclusion: In many cases, data recovery specialists are able to retrieve data using highly specialized tools and their deep knowledge of file and storage systems to find a workaround to solve the problems with the corrupted data.
When valuable data is lost, you should contact a professional data recovery service provider like Kroll Ontrack. Their experts will give you a sound assessment of data recoverability in a very short period of time.
Picture copyright: Kroll Ontrack GmbH using MOSH