Linked List File Management System

Duration: 2 min

This video lesson is available to enrolled students.

Inside: a video lesson and guided study material.

Module outline

Communication Round: Vocabulary, Subject Verb Agreement (Verb Noun Agreement), Tenses, Comprehension / Reading Comprehension / Unseen Passages (Critical Reasoning) (Paragraph Questions), Cloze Test (Cloze Passage), Sentence Correction (Error Correction), Sentence Completion (Fill in the blanks), Sentence Re-arrangements (Para Jumbles) (Narrative Sequencing), Direct and Indirect Speech, Active Passive Voice (Voice), Verbal Analogy (Word Based Analogy), Articles, Preposition, Conjunction, Sentence Construction, English Writing Ability, Communication Assessment
Quantitative Aptitude: Ratio and Proportion (Ratios), Divisibility Rules, Data Interpretation, Mixture and Alligation, Permutation and Combination, Logarithm, Number System, HCF LCM, Speed Time and Distance, Percentage, Average, Powers and Exponents (Surds and Indices), Time and Work, Mensuration and Geometry, Age Problems, Pipe and Cistern, Probability, Profit and Loss, Simple Interest and Compound Interest, Algebra
Analytical and Logical Reasoning: Series (Number and Letter Series) (Numerical Relations and Reasoning), Coding Decoding, Data Sufficiency, Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning), Directions (Direction Test), Ranking, Order and Sequence, Deductive and Inductive Reasoning (Logical Deduction and Induction) (Prepositional Reasoning), Selection Decision Table (Decision Making), Logical Sequence Of Words, Puzzle Solving (Puzzles), Syllogisms, Seating Arrangements, Calendar, Clock, Blood Relations, Cubes & Dices, Venn Diagram, Analytical Reasoning (Counting Figures Reasoning)
Cognizant Gaming Aptitude: Gamified / Game Based Aptitude
Java (Cluster 1): Java
ANSI SQL MySQL (Cluster 1,2,3): SQL
HTML, CSS, JavaScript (Cluster 1,3): HTML, CSS, JavaScript
Python (Cluster 2): Python for Placements by Yash Sir
Cloud Fundamentals (Cluster 2): Emerging Tech Trends
C# (Cluster 3): C#
OOPs: Object Oriented Programming (OOPS)
Technical Assessment (Coding): Coding Questions by Yash Sir, C Programming by Yash Sir, Programming in C++, Pseudo Codes
Data Structures: Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing
DBMS: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, File Organization & Indexing, Relational Algebra, Relational Calculus, Transaction Management, Concurrency Control, Database Recovery, ORDBMS, Database Security & Authorization, Query Processing & Optimization, Enhanced Data Models, Data Warehousing & Mining, Big Data Systems, NoSQL
Operating Systems: Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Deadlock, Threads & Process Creation, Memory Management, Virtual Memory, Disc Scheduling, File Management, Windows OS, Linux OS, Security, Distributed Systems, Virtual Machines
Computer Networks: Introduction to CN, Data Communication, DLL: Access Control, DLL: Flow Control, DLL: Error Control, DLL: Framing, Data Link Layer - Ethernet, Net Layer: IPv4 & Proto, Net Layer: IP Addressing, Net Layer:Routing Protocol, Transport Layer Services, TL: Congestion & UDP, Application Layer, Hardware basics, Network Security, Mobile Technology, Cloud Computing and IoT, Cyber and Info Security

AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

The video introduces the Linked List method for free-space management. The instructor explains that this approach links all free disk blocks together. A pointer to the first free block is kept in a special location on the disk and cached in memory. The first block in the list contains a pointer to the next free block, creating a chain. The lecture references a specific example where blocks 2, 3, 4, 5, 8, 9, 10, 11, 12, 13, 17, 18, 25, 26, and 27 are free, while the rest are allocated. The visual aid shows a disk cylinder with arrows connecting these specific free blocks to illustrate the linked structure.

Chapters

0:00 – 1:48 00:00-01:48
The instructor introduces the Linked List approach for free-space management. The slide text states, 'Another approach to free-space management is to link together all the free disk blocks, keeping a pointer to the first free block in a special location on the disk and caching it in memory.' He explains that the first block contains a pointer to the next free disk block. The diagram on the right shows a disk cylinder with a 'free-space list head' pointing to block 2. Arrows connect block 2 to 3, 3 to 4, 4 to 5, and so on, following the sequence of free blocks listed in the text: 2, 3, 4, 5, 8, 9, 10, 11, 12, 13, 17, 18, 25, 26, and 27. The instructor gestures towards the diagram to demonstrate how the blocks are linked sequentially, skipping over the allocated blocks (like 0, 1, 6, 7, etc.). This visualizes the concept of a linked list where each node (free block) points to the next available node. He emphasizes that this structure allows the system to find free space by following the chain of pointers rather than scanning a bitmap.

The lesson effectively demonstrates how a linked list organizes free disk space by chaining free blocks together. By maintaining a head pointer and storing the next block's address within each free block, the system can efficiently traverse available space without needing a separate bitmap or complex structure for every block. This method is particularly useful when free blocks are scattered across the disk, as it avoids the overhead of maintaining a large bitmap for sparse free space. The instructor's use of the disk cylinder diagram helps clarify how the logical link structure maps onto the physical disk layout, showing that the order of blocks in the list does not need to match their physical location on the disk. This flexibility is a key advantage of the linked list approach for free-space management.