Question

A program requires more memory than the available physical memory. The system allows execution by loading only required parts of the program into memory while keeping the rest on disk. This mechanism is known as?

• A. Paging
• B. Virtual Memory
• C. Deadlock
• D. Multiprocessing

Hint:

While "Paging" is a specific method used to implement this, "Virtual Memory" is the name of the general mechanism that allows the execution of processes larger than physical memory.

Answer 1

The Correct Option is B

Concept: Virtual memory is a memory management capability of an operating system that uses hardware and software to allow a computer to compensate for physical memory shortages.
• Logical vs Physical: It creates an abstraction of the main memory for the programmer.
• Address Space: The "logical address space" can be much larger than the "physical address space."
• Storage: It temporarily transfers data from random access memory (RAM) to disk storage.

Step 1: Understanding the memory constraint.
Programs often exceed the capacity of the installed physical RAM. Without an abstraction, such programs would fail to load or execute.

Step 2: Identifying the mechanism of partial loading.
The OS divides the program into smaller pieces (pages or segments). Only the active parts needed for execution are swapped into physical RAM. This process is known as "Demand Paging," which is a core component of Virtual Memory.

Step 3: Defining the outcome.
This provides the "illusion" of a very large memory to the user and the software. Virtual Memory is the overarching term for this specific management strategy.