Why Disk Utility Does Not Have ‘Drive Defrag’ Option

The ‘Disk Utility’ of your Mac OS X contains various options for maintaining and managing your hard drive, but it does not consists of any option to defrag the drive, have you ever thought why? Many of you may answer that Mac based hard drives do not get fragmented and this is the reason why ‘Disk Utility’ does not have any such option. Well, this is not true completely, as the basic data storage mechanism of hard drives make them fragmented within a period of time.

According to this mechanism, your hard drive stores data from top to bottom and if any data is deleted, then the data below it cannot be shifted to the deleted data’s space automatically. This naturally creates fragmentation in between the files as you keep on saving and deleting data on your hard drive. Therefore, this again says that hard drives get fragmented overtime, then why the useful utility of Mac does not have any option for defragmentation. Well, this is because the file system of Mac has some inbuilt safeguards that prevent it from getting fragmented easily:

1. The HFS+ file system of your OS X is designed in a way that it does not save a new file in a recently freed space. This prevents hard drive from getting fragmented at file level as they are not stored just to adjust them to small space left on the drive. Moreover, it searched for large contagious area on its hard drive and saves the complete file there.
2. OS X automatically collects all the small files scattered over the hard drive and saves them on a larger area on the drive. Moreover, while moving these files to a larger area, it defragments them (if it finds any fragments).
3. Moreover, the OS X checks for highly fragmented file, when you access it and if it finds large fragments (more than 8) in it, then it automatically defrags it.
4. The ‘Hot File Adaptive Clustering’ feature of Mac OS X keeps an eye on all recently used files that do not change frequently, and moves these files to fast accessed ‘hot zone’ on your hard drive. While moving these files to hot zone, Mac OS X also defrags them.

Therefore, these are the reasons due to which you do not require a special option as disk defragmenter for Mac. However, if your Mac is having less than 10% free space or you have big amount of large files like video files stored on it, then you may require a professional defrag tool as in such situations these safeguards fail to do the needful.