There are a plethora of things that can corrupt data on your hard drive, such as power outages, disgraceful shutdowns, hardware problems, bad programming, and more. When such events take place on a Mac, you are left with a corrupt hard drive directory that has serious implications for your system. A corrupt directory can potentially damage your files by overwriting them with new data. It can cause some of your files to go missing or being moved to a different location on the drive.
Every item on the OS X drive is represented by catalog records. These records are organized in a B-Tree structure called catalog B-Tree. The information in the directory is built by scanning and searching the catalog B-Tree. If this B-Tree structure gets damaged or the catalog records become corrupt, you will be unable to locate and access files stored on your hard drive.


