Virtual Memory

• Virtual memory is a technique that allows the execution of processes that are not completely in memory.
  • One major advantage of this scheme is that programs can be larger than physical memory.
  • Further, virtual memory abstracts main memory into an extremely large, uniform array of storage, separating logical memory as viewed by the user from physical memory.
• Virtual memory also allows processes to share files easily and to implement shared memory.
• Virtual memory is not easy to implement, however, and may substantially decrease performance if it is used carelessly.