What is the role of inode in file systems and why is it needed?

An inode stores metadata about a file or directory in Unix-like file systems.

It contains:

• File type (regular file, directory, symbolic link, etc.).
• Access rights and owner.
• File size.
• Creation, modification, and access times.
• Number of hard links.
• Pointers to data blocks on disk where the file content is stored.

An inode is necessary because:

• It separates metadata from the actual file content, allowing efficient file management.
• Each file or directory has a unique inode number within the file system.
• File names are stored in directories and linked to their respective inode numbers, not the physical location of data. This allows multiple names (hard links) for a single inode/file.
• It enables the system to quickly locate data blocks associated with a file without scanning the entire file system.

Example usage:

# Get the inode number of a file
stat -c "%i" /path/to/file

# Find files by inode number in the current directory and subdirectories
find . -inum <inode_number>