Fundamentals · Medium · Free
What is a file system? Explain inodes, directories, and permissions.
FresherFundamentalsOperating Systems
File systems
A file system organizes data on disk into files and directories. Inodes store metadata (permissions, size, block pointers); directory entries map names → inode. Permissions read/write/execute for user/group/other (chmod).
- Inode: unique ID per file; hard links share inode.
- Path lookup: walk directory entries (/home/user/app.log).
- Permissions: rwx bits—why 755 on scripts matters.
Example:
ls -li shows inode numbers—great live demo if allowed.