SSC IMD SA 2017 – Question 129

Which of the following statements is true?
A: To create a file, space needs to be allocated in the file system.
B: To create a file, an entry for the new file must be made in the directory.

• Only A
• Only B
• Both A and B
• Neither A nor B

Detailed Explanation:

The correct answer is c) Both A and B (A और B दोनों).

File Creation Mechanics in Operating Systems:
When an application creates a new file via a system call (e.g., open(..., O_CREAT) or creat()), the file system must perform two mandatory steps:

• Space Allocation (Statement A): Storage space must be allocated in the file system structures. This includes allocating an index node (inode in UNIX/Linux) or Master File Table (MFT) record in NTFS, along with reserving data blocks on disk to store the file’s content.
• Directory Entry Creation (Statement B): An entry linking the human-readable file name to its assigned unique file identifier (inode number or block pointer) must be written into the directory structure where the file resides.

Without space allocation, data cannot be held; without a directory entry, the file cannot be indexed or located. Hence, both statements are true.