A. Logical File System
B. File Organization Module
C. Basic File System
D. I/O Control
E. Application Programs
Choose the correct answer from the options given below:
Understanding the OS Layered File System Hierarchy
The question asks us to determine the correct order of layers in a typical layered file system within an operating system. This hierarchy represents how file system operations are processed, starting from user applications down to the physical storage hardware.
Explaining the File System Layers
Let's define each component provided:
- E. Application Programs: These are the highest-level software entities that interact with the file system to perform tasks like creating, reading, writing, or deleting files.
- A. Logical File System: This layer manages file and directory structures. It provides users and applications with a view of files as named collections of logical records, handling tasks like file naming, directory maintenance, and access control.
- B. File Organization Module: This layer is responsible for the physical arrangement of files on the storage device. It manages how logical records are mapped to physical blocks on the disk, handles file space management (tracking free and used blocks), and determines the allocation strategy for files.
- C. Basic File System: This layer translates logical block numbers (provided by the File Organization Module) into physical sector/track addresses and issues generic commands to the I/O device controllers to read or write data blocks.
- D. I/O Control: This is the lowest layer, which includes the device drivers and interrupt handlers. It understands the specifics of the storage hardware (like a hard disk drive or SSD) and translates the commands from the Basic File System into the specific electrical signals and operations required by the device controller.
Determining the Correct Hierarchy Flow
In a layered architecture, operations flow from the top layer downwards. When an application needs to access a file, the request passes through each layer sequentially until it reaches the hardware.
- The process begins with Application Programs (E) making a request.
- The Logical File System (A) interprets this request, handling directory lookups and file metadata.
- The File Organization Module (B) figures out which physical blocks on the disk correspond to the requested file data.
- The Basic File System (C) takes these block addresses and prepares the read/write commands.
- Finally, I/O Control (D) executes these commands on the specific storage device hardware.
Thus, the correct hierarchy is established by following this flow from the user-level application down to the device controller.
Conclusion on Layered File System Order
The sequence that correctly represents the layered file system hierarchy, moving from the highest level of abstraction to the lowest, is:
E (Application Programs) $\rightarrow$ A (Logical File System) $\rightarrow$ B (File Organization Module) $\rightarrow$ C (Basic File System) $\rightarrow$ D (I/O Control)
This matches the structure often found in operating systems for managing data storage efficiently and systematically.
Important Questions from File System
A mechanism for arranging controlled access to a shared resource, like a file, is called:
Which UNIX/Linux command is used to make all files and sub-directories in the directory “progs” executable by all users?
In Linux operating system environment ________ command is used to print a file.
Consider the following statements :
(a) UNIX provides three types of permissions
Read
Write
Execute
(b) UNIX provides three sets of permissions
permission for owner
permission for group
permission for others
Which of the above statement/s is/are true ?
Match the following WINDOWS system calls and UNIX system calls with reference to process control and File manipulation.
Windows
UNIX
A. Create-process( )
I. Open( )
B. WaitForSingleObject( )
II. Close( )
C. CreateFile( )
III. Fork( )
D. CloseHandle( )
IV. Wait( )
