- External Fragmentation – total memory space exists to satisfy a request, but it is not contiguous.
- Internal Fragmentation – allocated memory may be slightly larger than requested memory; this size difference is memory internal to a partition, but not being used.
- Reduce external fragmentation by compaction
- Shuffle memory contents to place all free memory together in one large block.
- Compaction is possible only if relocation is dynamic, and is done at execution time.
- I/O problem
*Latch job in memory
while it is involved in I/O.
*Do I/O only into OS
buffers.
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