Free Space Management

Duration: 2 min

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Inside: a video lesson and guided study material.

Module outline

  1. 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
  2. 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
  3. 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)
  4. Cognizant Gaming Aptitude: Gamified / Game Based Aptitude
  5. Java (Cluster 1): Java
  6. ANSI SQL MySQL (Cluster 1,2,3): SQL
  7. HTML, CSS, JavaScript (Cluster 1,3): HTML, CSS, JavaScript
  8. Python (Cluster 2): Python for Placements by Yash Sir
  9. Cloud Fundamentals (Cluster 2): Emerging Tech Trends
  10. C# (Cluster 3): C#
  11. OOPs: Object Oriented Programming (OOPS)
  12. Technical Assessment (Coding): Coding Questions by Yash Sir, C Programming by Yash Sir, Programming in C++, Pseudo Codes
  13. Data Structures: Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing
  14. 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
  15. 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
  16. 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.

This educational video segment focuses on the critical concept of Free-Space Management within operating systems. The instructor, Sanchit Jain Sir, explains the necessity of reusing disk space due to hardware limitations. He introduces the free-space list as the primary data structure used by the system to track available storage. The lecture details the entire lifecycle of a disk block, from its initial availability, through allocation for a new file, to its eventual removal from the list, and finally, its return to the list upon file deletion. This process ensures efficient utilization of limited physical storage resources.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The instructor starts by highlighting the constraint: Since disk space is limited, we need to reuse the space from deleted files for new files, if possible. He then defines the mechanism used to handle this: To keep track of free disk space, the system maintains a free-space list. He clarifies that this list records all free disk blocks—those not allocated to some file or directory. The process for creating a new file is described as a search operation: To create a file, we search the free-space list for the required amount of space and allocate that space to the new file. This section establishes the foundational logic of how the system identifies and assigns storage.

  2. 2:00 – 2:27 02:00-02:27

    The final part of the explanation covers the dynamic updates to the free-space list. The instructor states, This space is then removed from the free-space list immediately after allocation. He then describes the reverse action: When a file is deleted, its disk space is added to the free-space list. This ensures that the list remains current and accurate. The instructor underlines key phrases on the slide such as removed from the free-space list and added to the free-space list to reinforce the bidirectional nature of the management process. This completes the cycle of storage management.

The lecture provides a concise overview of how operating systems manage disk storage. By maintaining a free-space list, the system can efficiently allocate space for new files and reclaim space from deleted ones. The instructor emphasizes the continuous cycle of allocation and deallocation, ensuring that limited disk resources are reused effectively. This fundamental concept is crucial for understanding file system design and storage efficiency.

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