File Systems and Directory Operations Quiz

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Questions and Answers

What is the primary function of an executable file type?

To contain audio/video information

To store textual data

To compile source code

To run a machine language program (correct)

Which file extension is associated with multimedia files?

.exe

.mp3

.txt

.mov (correct)

Which of the following is NOT a directory operation?

Search for a file

Create a file

Transform a file (correct)

Delete a file

In a two-level directory system, how are files organized?

Files are categorized into user-specific directories Signup and view all the answers

Which attribute is NOT typically found in a device directory?

Creation date Signup and view all the answers

What organizational method does a tree-structure directory system utilize?

A hierarchy of directories Signup and view all the answers

What is one benefit of having a collection of files in a directory?

It allows for logical grouping of files by properties Signup and view all the answers

How does the operating system use file extensions?

To determine file type and associated operations Signup and view all the answers

What are the three main components of a file system?

Files, a directory structure, and partitions Signup and view all the answers

Which of the following correctly describes the primary function of a file system?

To manage and access data and programs Signup and view all the answers

What distinguishes logical storage units from physical storage units?

Logical storage units represent files mapped to physical devices Signup and view all the answers

Which type of file is organized as a sequence of subroutines and functions?

Source file Signup and view all the answers

What is the smallest element of logical secondary storage that data must be contained within?

File Signup and view all the answers

Which of the following types of information can be stored in a file?

Source programs, text, and sounds Signup and view all the answers

Which file type is comprised of a sequence of bytes organized into blocks?

Object file Signup and view all the answers

What type of file contains code sections that a loader can execute?

Executable file Signup and view all the answers

What is the primary purpose of creating a file in a file system?

To make an entry for the new file in the directory Signup and view all the answers

When repositioning within a file, what does this operation primarily change?

The current file position Signup and view all the answers

What occurs when a file is truncated?

The contents are erased but attributes are kept Signup and view all the answers

Which operation allows for adding new information to an existing file?

Appending to a file Signup and view all the answers

What is the result of deleting a file?

The directory entry for the file is erased and space is freed Signup and view all the answers

What does the operation of writing to a file require?

Specifying both the name and the information to be written Signup and view all the answers

What does the 'Get and Set file attributes' operation allow you to do?

View or change file properties like size and name Signup and view all the answers

Which operation involves creating a new file based on an existing one?

Copying of a file Signup and view all the answers

What is one of the main advantages of using the indexed access method?

It allows for quick searches based on the index. Signup and view all the answers

Which command would you use to change the age of a person named Ahmed to 50?

Update Tb1 set age = 50 where name = 'Ahmed'; Signup and view all the answers

Which of the following statements is a disadvantage of contiguous allocation?

Finding a suitable hole for new files can be difficult. Signup and view all the answers

What happens when using indexed access methods with large files?

The index size may become too large for memory. Signup and view all the answers

What format does each file prefer for efficient storage?

Contiguous allocation. Signup and view all the answers

Which method is NOT mentioned as a file allocation method?

Randomized Allocation. Signup and view all the answers

What is a key advantage of having a User File Directory (UFD) system?

Eliminates naming conflicts between files from different users Signup and view all the answers

How does the indexed access method enhance reading speed?

By providing pointers for each record. Signup and view all the answers

What is a common strategy for allocating space in contiguous allocation?

Best fit method for optimizing space. Signup and view all the answers

What is a disadvantage of a file system that uses User File Directories?

Users need to specify both username and filename to access another user's file Signup and view all the answers

What does the term 'absolute path name' refer to in file systems?

A path name that begins from the root directory Signup and view all the answers

Which of the following is a potential drawback of shared directories?

Deleting or updating shared files may lead to complications Signup and view all the answers

What characterizes a relative path name in a file system?

It begins from the current directory Signup and view all the answers

What is an advantage of allowing users to create an arbitrary number of subdirectories?

It helps users isolate similar files for easier organization Signup and view all the answers

Which of the following statements about file access methods is true?

File access methods dictate how files can be read and written Signup and view all the answers

What is an issue that may arise in a system where multiple users share files?

Files may be overwritten if names are the same Signup and view all the answers

What is the primary solution to external fragmentation?

Compacting all free space into one contiguous space Signup and view all the answers

Which of the following is a disadvantage of linked allocation?

Limited to sequential access Signup and view all the answers

What happens when pointers in a linked allocation are lost or damaged?

The file system may become unreliable Signup and view all the answers

In a file system with an index block, what information is stored in the directory entry?

The file name and the index block address Signup and view all the answers

What does the FAT (File Allocation Table) entry indicate for unused blocks?

A value of 0 Signup and view all the answers

What needs to be done if the FAT is damaged?

Access to all files will be lost Signup and view all the answers

Which of the following is NOT an advantage of linked allocation?

Reduced space for management overhead Signup and view all the answers

What is required for the FAT to function efficiently?

It must be cached in memory Signup and view all the answers

Study Notes

Operating Systems

The lecture covered a range of topics related to operating systems, specifically focusing on file system management.
A file system consists of files, each storing related data, a directory structure organizing files, and partitions for large collections of directories.
The fundamental function of a file system is managing and accessing data and programs.
Physical storage units are the actual storage media (disks, tapes, optical drives), while logical storage units are files mapped onto physical devices by the operating system.
A computer file is a named collection of related information stored on secondary storage, acting as the smallest logical storage unit.

File System Parts

File systems are composed of files, each storing related data.
Directory structures organize and provide information about all files within a system.
Partitions separate physically or logically large collections of directories.

File System Function

The file system manages and accesses data and programs.

Physical vs. Logical Storage Unit

Physical storage units are the physical devices used for storage.
Logical storage units are files.
The operating system maps files onto physical storage devices.

Definition of Computer File

A file is a named collection of related information stored on a secondary storage device.
Files are sequences of bits, bytes, lines, or records defined by their creator and user.
Data cannot be written to secondary storage unless it's part of a file.
Typically, files represent programs (source and object code) and data.

File Types

File types include source programs, object programs, executable programs, and data files (containing numeric data, text, images, and sound).

File Structure

Files have defined structures based on their type.
Text files are sequences of characters.
Source files include subroutines and functions.
Object files are in a format understandable by the linker.
Executable files are code sections executable by the loader.

File Attributes

Files have attributes like a name (per user), an identifier (unique to the system), a data type, location on a physical device, size, protection info, and time/date information (creation, modification, last use).
File information is maintained in directory structures on secondary storage.
File attributes are included in their respective directory entries.

Files Operations

Operating systems provide system calls for creating, writing, reading, repositioning, deleting, and truncating files.
These operations involve 12 different file actions.

Open-File-Table

File operations often involve searching the directory.
The open-file-table (a small table in the operating system) caches information about open files, speeding up subsequent operations.
When a file operation occurs, the file is specified by its index in the open-file-table, avoiding directory searches.
OS includes file types within the filename (e.g., "image.png"). The name and extension are separated by a period.

How OS implements File Types

File types are often implemented by including the type as part of the filename.
The naming convention uses a period to separate the name from the extension.

Why OS implements File Types

The OS uses extensions to determine file types and the operations that can be performed on them.
Extensions indicate the appropriate application programs for opening and working with files.

Common File Types

Common file types include their extensions and functionalities—for example, .exe files are executable, and .txt files are text files.

Why Files must have Extension

Extensions help determine a file type.
Determine how files can be processed.
Indicate which application program should open the files.

How OS organizes Files

Operating systems organize files in large storage units—partitions or volumes—which behave as separate storage.
Directories are a key part of how files are organized.

Directory Operations

Directory operations include searching for a file, creating a file, deleting a file, and listing a directory /renaming a file.

Directory Content

Device directories contain information like file name, type, address, current and maximum length, date last accessed and updated information, owner info, and protection.

Advantages of Directories

Directories improve efficiency by allowing quick file location.
They aid in naming, permitting multiple users to have different files with the same name (e.g., 'mailbox' for each user).
Directories facilitate grouping similarly-used files.

Directory Structure

Operating systems use diverse directory systems (single-level, two-level, tree-structure, and acyclic-graph).

Single-Level Directory System

One directory that collects all files.
Simpler for single-user systems, useful in early personal computer systems.
Can lead to conflicts when multiple users share a system.

Two-Level Directory System

Combines a master directory (MFD) with user directories(UFDs).
Helps avoid naming issues
Requires users to specify both user directories and the file name whenever accessing another user's files.

Tree-Structure Directory System

Files organized in a hierarchical tree structure, useful for files.
Allow users to create subdirectories.
Using unique directory names (paths) avoid name conflicts.

Acyclic-Graph Directory Systems

Enable file and directory sharing amongst different users.
Allows directories and files to be shared.
Offers flexibility(e.g shared directories).

File Access Methods

Three common methods for accessing files: sequential, direct (random), and indexed.
These methods affect how files are read and written on a disk.

Sequential Access Method

Files processed sequentially, block by block.
Cannot access a specific record until previous blocks are read.

Direct Access Method

Records accessed directly via "record numbers."
Suitable for applications where random access to parts of a file are common.

Indexed Access Method

Files contain indexes, giving access to the indexed record quickly.
Not well suited for large files: indexes can become too large to keep in memory

Disk Allocation Methods

Methods used to allocate space on the disk, includes contiguous, linked, indexed, file allocation table (FAT) methods, disk space.

Contiguous Allocation Method

Files stored in contiguous disk blocks.
Requires knowing the filesize during creation.

Linked Allocation Method

Files stored in non-contiguous blocks, linked by pointers.
Allows files to grow without need to know the file size.
Not suitable for direct access.

Indexed Allocation Method

Files have an index block, storing the addresses of the file's blocks
Easy to access files directly, good for searching.
Index block can be large, potentially limiting applicability to medium-sized files.

File Allocation Table (FAT)

FAT is a table that tracks file locations on a disk
Directory entries point to the starting block of a file, and the FAT records the rest of the blocks(sequential).
FAT must be loaded into memory to operate(can be a drawback when dealing with large amounts of data).

Data Reliability/Protection

Data reliability measures include backing up files, disks and data, and making periodic copies to ensure data loss is minimized.
Data protection mechanisms control access to files/folders to avoid unauthorized operations or damage.

Access Control List (ACL)

ACL is a list of users/groups and their access permissions (e.g write, read, execute, delete) for a file/directory.

Passwords

Passwords can be used to control file access.

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Description

Test your knowledge on file systems, directory operations, and file types with this comprehensive quiz. Covering questions on executable files, multimedia file extensions, and organizational methods, this quiz will enhance your understanding of how file systems work. Perfect for students in computer science or information technology courses.