File Systems and Its types

File Systems 

A file is a named collection of related information, including programs. Data can be numeric, alphabetic, or alphanumeric. The file system allows file and directory management, disk space allocation, and maps files to physical storage devices for uniform access. 

Tape-based Systems 

Early tape-based file systems were simple but inefficient. Multiple small files stored on large tapes required a directory for file location, making file retrieval time-consuming. Modifying files required copying the entire tape. Tapes were used for data transport, backup, and archival storage. 

Disk-based Systems 

Disk-based systems resolve tape issues by using disks divided into tracks and sectors, enabling efficient read/write operations. A sector is the smallest unit of information which can read from or write on to the disk. Each platter has two surfaces. To access a sector, we must specify the surface, track and sector. The time required for read-write heads to move to the correct track is seek time. Then they electronically switch to the correct surface. Then we wait for the requested sector to rotate below the heads. This is called latency time (or rotational delay). Each block is a sector. If S is number of sectors per track, t is number of tracks per cylinder, then disk address of cylinder i, surface j, sector k is block number b,  

b = k + s x (j + i x t)