File system fragmentation

In computing, file system fragmentation, sometimes called file system aging, is the tendency of a file system to lay out the contents of files non-continuously to allow in-place modification of their contents. It is a special case of data fragmentation. File system fragmentation increases disk head movement or seek time (where it applies), which are known to hinder throughput. In addition, file systems cannot sustain unlimited fragmentation. The correction to existing fragmentation is to reorganize files and free space back into contiguous areas, a process called defragmentation. In computing, file system fragmentation, sometimes called file system aging, is the tendency of a file system to lay out the contents of files non-continuously to allow in-place modification of their contents. It is a special case of data fragmentation. File system fragmentation increases disk head movement or seek time (where it applies), which are known to hinder throughput. In addition, file systems cannot sustain unlimited fragmentation. The correction to existing fragmentation is to reorganize files and free space back into contiguous areas, a process called defragmentation. In modern computers, with SSD 'disks' that do not rotate and are not really discs in the conventional sense, file system fragmentation isn't as much of a performance problem (that should be 'fixed'), as there is no movement of heads or discs. In fact, overly defragmenting such drives can slowly shorten their life-span. When a file system is first initialized on a partition, it contains only a few small internal structures and is otherwise one contiguous block of empty space. This means that the file system is able to place newly created files anywhere on the partition. For some time after creation, files can be laid out near-optimally. When the operating system and applications are installed or archives are unpacked, separate files end up occurring sequentially so related files are positioned close to each other.