File System Implementation MCQs

1. UNIX file permissions include:

a) Read, Write, Execute b) Create, Delete c) Allocate, Deallocate d) None

Correct Answer: a) Read, Write, Execute

Explanation:
UNIX systems use a basic permission system with read (r), write (w), and execute (x) permissions for owner, group, and others.

2. Access Control Lists (ACLs) provide:

a) Basic permissions b) Granular control c) No security d) None

Correct Answer: b) Granular control

Explanation:
ACLs extend basic permissions by allowing specific access rights to be defined for individual users and groups, providing finer-grained security control.

3. Contiguous allocation suffers from:

a) Internal fragmentation b) External fragmentation c) Both d) Neither

Correct Answer: b) External fragmentation

Explanation:
Contiguous allocation requires files to occupy consecutive disk blocks, leading to external fragmentation as free space becomes broken into small non-contiguous chunks.

4. Linked allocation uses:

a) Index blocks b) Pointers between blocks c) Bitmaps d) None

Correct Answer: b) Pointers between blocks

Explanation:
In linked allocation, each disk block contains a pointer to the next block in the file, creating a chain that can be non-contiguous.

5. A bit vector tracks:

a) File contents b) Free blocks c) Directory entries d) None

Correct Answer: b) Free blocks

Explanation:
A bit vector (or bitmap) uses one bit per disk block (0=free, 1=allocated) to efficiently track available space.

6. Grouping free blocks improves:

a) Speed b) Fragmentation c) Security d) None

Correct Answer: a) Speed

Explanation:
Grouping adjacent free blocks together (as in the counting method) speeds up allocation by reducing the number of individual block operations needed.

7. Linear list directories are:

a) Fast for large directories b) Simple but slow c) Complex but fast d) None

Correct Answer: b) Simple but slow

Explanation:
Linear lists store directory entries sequentially, making implementation simple but requiring O(n) searches for file lookups in large directories.

8. Hashing improves:

a) File creation b) Directory searches c) Permissions d) None

Correct Answer: b) Directory searches

Explanation:
Hash tables convert filenames to array indices, enabling O(1) average-case lookup time for directory entries (though collisions must be handled).

9. Inode-based systems store:

a) File metadata b) Directory structures c) Both d) Neither

Correct Answer: c) Both

Explanation:
Inodes (index nodes) contain file metadata (permissions, timestamps) and block pointers, while directory entries map names to inode numbers.

File System Implementation MCQs

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