---
title: "What is Belady's Anomaly in Operating System?"  
description: "What is Belady's Anomaly in Operating System?"  
author: "Kalin"  
published: 2022-04-04  
canonical: https://answers.mindstick.com/qa/96695/what-is-belady-s-anomaly-in-operating-system  
category: "troubleshooting"  
tags: ["troubleshooting", "operating systems"]  
reading_time: 1 minute  

---

# What is Belady's Anomaly in Operating System?

What is Belady's Anomaly in Operating System?

## Answers

### Answer by Hitesh Vohra

![What is Belady](https://answers.mindstick.com/questionanswer/e69c0a90-6289-4817-8630-51206a2d645a/images/49d32453-c9ac-420b-8462-0f31222757d7.png) **\**

- **Bélády's anomaly** is a phenomenon in computer storage where increasing the number of page frames leads to an increase in the number of page faults for specific memory access patterns.
- When employing the first-in-first-out (FIFO) page replacement mechanism, this is a regular occurrence.
- The page fault may or may not grow as the number of page frames increases in FIFO, however as the number of page frames increases in optimum and stack-based algorithms like LRU, the page fault reduces. In 1969, László Bélády demonstrated this.
- This is a regular occurrence in the page replacement methods listed below:
- Second chance method based
- on the first in, first out (FIFO) principle.
- Algorithm for replacing pages at random

## \

**Read More: [What is starvation in Operating System?](https://answers.mindstick.com/qa/96696/what-is-starvation-in-operating-system)**


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