About
cluster are the logical unit of file storage for the OS file system.
When writing and deleting, the creation of the clusters are not always:
- used as its full capacity
- and contiguous on the disk
Their is fragmentation.
The disk head needs therefore to move around in order to gather the data for the whole file.
Defragmentation is the OS file system process that moves cluster on a disk to make them full and contiguous with the premise to improve performance (Nowdays, not always true).
