← Operating Systems learning pathOperating Systems · Module 7 of 10
Virtual memory
Run programs larger than physical memory.
📖 Key ideas
- Virtual memory uses disk to extend RAM.
- Demand paging loads pages only when needed.
- Page fault: accessed page not in RAM.
- Page replacement: FIFO, LRU, Optimal.
- Thrashing: too much paging, little real work.
💡 Real-life example: Virtual memory is a study desk with a cupboard: books you need now on the desk, others in the cupboard.
Virtual memoryIllusion of large memory using disk
Page faultPage not in RAM
LRULeast Recently Used replacement
ThrashingExcessive paging