What is a file system?

An operating system’s structure and method for managing and arranging files on storage media is called a file system. It offers a method for managing storage device space as well as for storing, retrieving, and updating data.

What are the main types of file systems?

Some common types of file systems include:

• FAT (File Allocation Table): Used in older systems, compatible with various devices.
• NTFS (New Technology File System): Used in Windows systems; supports permissions, encryption, and large files.
• ext (Extended File System): Used in Linux; includes ext2, ext3, and ext4.
• HFS+ (Hierarchical File System): Used in macOS.
• APFS (Apple File System): Modern macOS file system optimized for SSDs.
• ZFS (Zettabyte File System): Known for data integrity and scalability.
• exFAT: Optimized for flash drives, supports large files, and is cross-platform.

What is the difference between NTFS and FAT32?

Feature	NTFS	FAT32
File Size Limit	No practical limit	4 GB
Partition Size Limit	16 TB or more	2 TB
Security Features	Supports permissions and encryption	None
Compatibility	Mainly Windows	Compatible with more devices

What is the purpose of journaling in file systems?

One method for preserving the file system’s integrity in the event of unforeseen malfunctions, such as power outages, is journaling. It maintains a diary, or log, of upcoming modifications so that they can be securely executed or reversed in the event of a system failure.

How does a file system allocate space?

File systems allocate space using various techniques:

• Contiguous Allocation: Files are stored in contiguous blocks of memory.
• Linked Allocation: Files are stored in blocks linked together via pointers.
• Indexed Allocation: Uses an index block to store pointers to file blocks.

What is the difference between hard links and soft links?

• Hard Link: Points directly to the data of a file; multiple hard links to the same file share the same inode.
• Soft Link (Symbolic Link): Points to the path of a file; it acts as a shortcut.

What is a mount point?

A mount point is a directory in a file system where additional file systems are attached. For example, in Linux, external drives are mounted at specific directories like /mnt or /media.

What is the role of metadata in file systems?

Metadata provides information about files and directories, such as:

• File name
• File size
• File type
• Permissions
• Timestamps (creation, modification, access)

What is a virtual file system (VFS)?

An abstraction layer called a virtual file system makes it possible to access many file systems consistently. Without having to worry about the underlying file system, it allows applications to interface with files.

How is data integrity ensured in modern file systems?

Modern file systems ensure data integrity using:

• Checksums for detecting and correcting errors.
• Journaling to recover from unexpected failures.
• Copy-on-Write (CoW) techniques in systems like ZFS and Btrfs.

What is in-memory file system (RAM disk)?

Instead of using actual disks for storage, an in-memory file system makes use of RAM. Although it is volatile—all data is destroyed when the machine is shut down or restarted—it is far faster than traditional storage.

What is the inode in a file system?

An inode is a data structure in Unix-like file systems that stores metadata about a file, such as:

• File size
• File type
• Permissions
• Timestamps
• Pointers to the data blocks