Describe fragmentation

Question

Describe fragmentation? Different kind of fragmentation?

Answer 1

Fragmentation takes place in a dynamic memory allocation system while many of the free blocks are too small to satisfy any request.

External Fragmentation: External Fragmentation happens while a dynamic memory allocation algorithm allocates some memory and small piece is left over that cannot be used effectively. If too much external fragmentation takes place, the amount of usable memory is reduced drastically. Total memory space exists to satisfy a request, however it is not contiguous.

Internal Fragmentation: Internal fragmentation is the space wasted within allocated memory blocks due to restriction on the allowed sizes of allocated blocks. Allocated memory might be slightly larger than requested memory; this size difference is memory internal to a partition, however not being used