MINIX file system

The Minix file system is the file system of the former teaching Minix operating system.

History

Minix is programmed since the 1980s as a Unix -like operating system completely by Andrew S. Tanenbaum as a teaching system (the current version is Minix3 from the year 2005).

The Minix file system was designed for Minix. It is based on the fundamental structures of the Unix file system, with the omission of complex functions as clearly structured the source code for the purposes of teaching the use of Minix and easy to make. Therefore, it has a series of limitations:

  • A partition can not be larger than 64 MB in size ( cluster addresses are represented as 16 -bit integers ).
  • File names can not be longer than 14 or 30 characters.
  • File associations ( "Symbolic links", also called " symlinks ") are not used.

This file system from Linux to the introduction of the extended file system (see also: second extended file system ) used in April 1992 as standard and is to this day still common in ( bootable ) floppy disks, partly for RAM disks and other fields of application low because of the used for the management of space needed.

Construction

A Minix file system consists of six components:

  • The boot sector which is always placed in the first block. It contains the boot loader, which the operating system loads when the computer starts and restarts.
  • The superblock contains information about the file system. These data allow each operating system to locate and process the other structures of the file system. Examples of the data of the superblock are the number of inodes and clusters.
  • The inode bitmap is a simple representation of the status of all inodes. It is only shown if an inode is ("1" ) or free (" 0").
  • The cluster bitmap has the same structure as the inode bitmap, but represents the status of the cluster in the data area
  • The inodes area. Every file and directory is represented by at least one inode, which in turn includes the following metadata:
  • Type (file, directory, device file or pipe )
  • User and group ID
  • Timestamp of the last change
  • Access permissions
  • Size
  • Number of links
  • List of addresses that point to the cluster in the data area in which the inode corresponding to the content data is stored.
  • The data area is the part of the file system, which occupies naturally the largest square. Here, the actual content of the files and directories will be stored.

(Note: In English texts of the clusters in terms of Minix is usually referred to as a " zone". )

Data cluster Filename ext2 RAM drive
574490
de