File System Implementation - Deep Dive Into Persistent Storage Management

This section provides an extensive overview of file system implementation, focusing on how operating systems manage persistent data on secondary storage, including their structure, metadata, allocation methods, and free-space management.

File System Structure - The Architectural Blueprint Of Data Persistence

This section delves into the layered architecture of file systems, outlining how they abstract and manage persistent data storage on secondary devices.

Layers Of The File System: A Hierarchical Abstraction

This section discusses the layered architecture of modern file systems, identifying five key layers that facilitate data management.

Application Programs (User Interface Layer)

This section explores the role of application programs in interacting with the file system through the user interface layer, outlining the standard system calls and user perspectives on file management.

Logical File System (File-Organization Module)

The Logical File System layer translates user file operations into manageable formats while handling metadata and directory structures.

Basic File System (I/o Control Layer)

This section discusses the Basic File System (I/O Control Layer) as a crucial component in translating logical file requests into physical disk operations.

Device Drivers

Device drivers are the crucial software layer that facilitates communication between the operating system and hardware devices, translating generic commands into hardware-specific actions.

Hardware (Storage Devices)

This section discusses the physical components of storage devices integral to file system operations, including unique characteristics and components for data management.

On-Disk Structure: Essential Metadata For File System Operation

This section explains the critical metadata structures required for file system operations, detailing the purpose and content of key components like the boot block, super block, inodes, and data blocks.

Boot Block

The Boot Block is a critical component located at the beginning of a disk partition, housing the boot loader necessary for the system startup.

Super Block (Or Volume Control Block)

The Super Block is a critical metadata structure in file systems, essential for managing and understanding the characteristics of the file system's volume.

Inodes (Index Nodes - Unix-Like File Systems) / File Control Blocks (Fcbs - General Term)

Inodes and File Control Blocks are critical structures that store metadata about files and directories in file systems, enabling effective data management.

Data Blocks

This section outlines the internal structures and metadata associated with file systems, focusing on the management of data blocks, inodes, and relevant metadata necessary for file system operations.

Directory Implementation - The Catalog Of Files

This section focuses on the implementation of directories in file systems, detailing how they map human-readable file names to file system identifiers.

Linear List (Of Directory Entries)

This section covers the linear list implementation of directory entries in file systems, explaining its mechanisms, advantages, and disadvantages.

Hash Table (For Directory Entries)

This section discusses the implementation of directories using hash tables, explaining how file names are hashed to create a directory index that optimizes lookup and creation speeds.

Allocation Methods - Managing File Data On Disk

This section details the different allocation methods for storing file data on disk, emphasizing contiguous, linked, and indexed allocations.

Contiguous Allocation

Contiguous allocation is a method where each file occupies a single, unbroken set of disk blocks for efficient data access.

Linked Allocation

Linked allocation allows files to be stored as a linked list of disk blocks, enabling them to be scattered across the disk while maintaining order with pointers.

Indexed Allocation

Indexed allocation is a file management method where all pointers to a file's data blocks are organized in a dedicated index block, enhancing both access speed and flexibility in file growth.

Free-Space Management - Keeping Tabs On Unused Disk Space

This section discusses methods for effectively tracking free disk space, crucial for file allocation management.

Bit Map (Bit Vector)

This section explains the concept of bit maps as a method for managing free disk space in file systems, highlighting their structure, advantages, and disadvantages.

Linked List (Of Free Blocks)

This section discusses the linked list method for managing free disk blocks in storage systems, detailing its mechanism, advantages, and disadvantages.

Grouping

Grouping improves free space management in file systems by storing addresses of multiple free blocks, reducing disk I/O operations.

Counting

The counting method in free-space management optimizes the allocation of contiguous disk blocks by maintaining an efficient list of free blocks using tuples.