What is the purpose of file types like .exe, .jpg, and .txt in an operating system?
Describe the structure of a file system and explain the role of directories.
Explain the three main storage allocation methods used by an operating system.
What is defragmentation, and how does it improve system performance?
How does an operating system ensure file security?
Answers
Answer: File types indicate the format and purpose of files, helping the OS identify how to process or open them (e.g., .exe for executables, .jpg for images, .txt for text).
Description: File extensions allow the OS to associate files with specific applications. For instance, .exe files are run as programs, while .jpg files are opened by image viewers, streamlining file handling.Answer: A file system organizes data on storage devices using a hierarchical structure of directories (folders) that contain files and subdirectories.
Description: Directories act like containers, organizing files for easy access. For example, a file system like FAT32 uses a tree-like structure to store and retrieve data efficiently.
Image Placeholder: [Insert diagram of a file system hierarchy]Answer: The three methods are:
Contiguous allocation: Stores a file in consecutive disk blocks.
Linked allocation: Stores file data in non-consecutive blocks linked by pointers.
Indexed allocation: Uses an index block to store pointers to file data blocks.
Description: Contiguous allocation is fast but prone to fragmentation. Linked allocation avoids fragmentation but is slower, while indexed allocation balances speed and flexibility.
Answer: Defragmentation reorganizes fragmented files on a disk to store them contiguously, reducing access time and improving performance.
Description: Over time, files get scattered across a disk, slowing access. Defragmentation consolidates files, as seen in tools like Windows Disk Defragmenter, enhancing read/write efficiency.Answer: The OS uses passwords, access privileges, and encryption to restrict file access to authorized users only.
Description: File security prevents unauthorized access or modifications. For example, Windows uses NTFS permissions to set read/write access for specific users or groups, ensuring data protection.