What is internal fragmentation in a partitioned main memory?

Internal fragmentation is the unused space left inside a partition too large for its process. The wasted space cannot be given to any other program.

What is external fragmentation?

External fragmentation is free space scattered between partitions in small unusable pieces. The total free memory may be large while no single gap is big enough.

Give one consequence of dividing memory into too many small partitions.

A large program cannot be loaded because no single partition is big enough. The program waits even though enough memory is free in total.

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Interrupts, Memory Management and Scheduling

Partitioning main memory

3 things to know
Component 2

Overview

Partitioning main memory, difference between fixed and variable partitioning and internal fragmentation in a partitioned main memory.

What you need to know

Answer each one before you reveal it.

Your recallNot started

Key term

What is meant by partitioning main memory?

Key term

Give two reasons main memory is partitioned.

Key term

Explain the difference between fixed and variable partitioning.

Questions from this subtopic

Each one with the model answer underneath.

1
What is meant by partitioning main memory?
Model answer
Memory partitioning is the division of main memory into separate areas, each holding one process. The operating system allocates a partition to every program it loads.
2
Give two reasons main memory is partitioned.
Model answer
Partitions let several programs stay resident at once so the processor is rarely idle. Partitions also keep each program's data separate from the others.
3
Explain the difference between fixed and variable partitioning.
Model answer
Fixed partitioning divides memory into areas of a size decided in advance. Variable partitioning gives each process a partition matching the size it actually needs.
4
What is internal fragmentation in a partitioned main memory?
Model answer
Internal fragmentation is the unused space left inside a partition too large for its process. The wasted space cannot be given to any other program.
5
What is external fragmentation?
Model answer
External fragmentation is free space scattered between partitions in small unusable pieces. The total free memory may be large while no single gap is big enough.
6
Give one consequence of dividing memory into too many small partitions.
Model answer
A large program cannot be loaded because no single partition is big enough. The program waits even though enough memory is free in total.

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