What is an INode?

An INode, most commonly referred to as an Index Node, is a fundamental concept in file systems, particularly those used by Unix and Linux operating systems. It serves as a data structure that stores information about a file or a directory, including its size, access permissions, ownership, and pointers to the actual data blocks where the file's content is stored.

The INode allows the file system to efficiently manage files, facilitating quick access and modification operations. When a file is accessed, the operating system uses the INode to retrieve file metadata and locate the data blocks associated with that file. This structure is crucial for maintaining the integrity and organization of the file system, ensuring that data can be accessed accurately and efficiently.

In the context of filesystem design and performance, understanding the role of the INode helps in recognizing how files are stored and accessed, which is vital for system performance tuning and troubleshooting.