What is an Inode?
An inode is a data structure used by Linux and Unix file systems to store metadata about a file or directory, including its size, ownership, permissions, and location on disk. Every file and directory on a Linux server has a unique inode number that the operating system uses to manage and retrieve it.
How Does Inode Work?
Inodes are fundamental to how Linux file systems like ext4 organize data. Each inode stores critical metadata such as file permissions, timestamps, owner and group IDs, and pointers to the actual data blocks on the disk. Notably, the inode does not store the file name itself; instead, directory entries map human-readable file names to their corresponding inode numbers.
In a web hosting context, inode limits are an important consideration. Many shared hosting providers impose inode limits to prevent any single account from consuming excessive file system resources. Exceeding your inode limit can prevent you from creating new files, receiving emails, or performing backups, even if you still have available disk space.