The process of files getting corrupted resulting from some hardware or software failure is known as data corruption and this is one of the main problems which Internet hosting companies face since the larger a hard disk drive is and the more info is filed on it, the more likely it is for data to be corrupted. There are several fail-safes, still often the info gets corrupted silently, so neither the file system, nor the admins notice a thing. Thus, a corrupted file will be handled as a regular one and if the hard disk drive is a part of a RAID, that particular file will be copied on all other drives. In theory, this is done for redundancy, but in reality the damage will be worse. When some file gets corrupted, it will be partly or fully unreadable, so a text file will no longer be readable, an image file will show a random blend of colors in case it opens at all and an archive will be impossible to unpack, and you risk losing your content. Although the most commonly used server file systems have various checks, they quite often fail to identify a problem early enough or require an extensive time period to be able to check all the files and the hosting server will not be operational for the time being.