(External) memory fragmentation is a long-standing Linux kernel programming issue. As the system runs, it assigns various tasks to memory pages. Over time, memory gets fragmented, and eventually, a busy system that is up for a long time may have only a few contiguous physical pages.
Do I need to defrag in Linux?
Although Linux file systems don’t need defragmentation as much or as often as their Windows counterparts, there’s still a possibility that fragmentation may occur. It could happen if the hard drive is too small for the file system to leave enough space between the files.
What is Unix fragmentation?
Fragmentation comes about when a system cannot or will not allocate enough contiguous disk space to store an entire file in a single location on a disk.