Organization and components of file systems
File system structure refers to the organization and components that make up a file system on secondary storage. A typical file system consists of several key components: boot control block (contains information needed to boot the OS from that volume), volume control block (contains volume details like number of blocks, block size, free block count), directory structure (organizes files and contains metadata about files), and file control blocks (contain file-specific information like ownership, permissions, size, and location data). File systems are typically organized in layers: the I/O control layer handles device drivers and interrupt handling, the basic file system layer issues generic commands to device drivers, the file organization module understands files and logical blocks, and the logical file system manages metadata information. Modern file systems often use journaling to maintain consistency by logging changes before committing them to the main file system. File systems also implement various on-disk structures like superblocks (containing file system metadata), inode tables (storing file metadata), and data blocks (storing actual file content). Understanding file system structure is essential for system administrators for troubleshooting, performance tuning, and data recovery, and for developers working with low-level file operations or implementing custom storage solutions.