Linux File Systems

File Allocation Table (FAT)

A typical cluster size is 2048 bytes, 4096 bytes or 8192 bytes. Entries are 16 bits in length.

Third Extended File System (EXT3)

All features of EXT3 with added journaling feature

ReiserFS

offers better disk space utilization, better disk access performance, faster crash recovery and reliability through journaling.

boot block

Code that initiates the boot process. each partition contains a boot block

FAT32

Files Allocation table entries are 32 bits in length Largest size hard disk supportable is 2 terabytes More efficent then FAT

Partition Table

Gives the starting and ending address of each partition is stored at the end of the MBR.

Second Extended Files System (EXT2)

Popular linux files system, designed by Stephen Tweedie Max disk size, 4 terabytes Max Files size: 2 gb max file name: 255 characters

PID

Processor ID

What does the files system do?

Provides a collection of files, each storing related data and a directory structure, which organizes and provides information about all the files in the system.

Master Boot Record (MRB)

Sector 0 of the disk, is used to boot the operating system. Each disk has 1.

What is used for mass back up of data?

Sequential storage media

Direct Access storage device (DASD)

any one file or program can be written or read independently of its position on the storage medium. Magnetic disk is most popular type.

Sequential Storage Media

Type of storage tape, allows data to be written or read in one sequential stream from beginning to end. Should you desire access to a block of data in the middle of the tape, you must scan all preceding data on the tape to find the block of interest

New Technology File System (NTFS)

Used by Windows Nt/200 Operating system. Offers a # of improvements over FAT, in terms of performance, extendability and security. Information about the files clusters and other data is stored with each cluster, not just a governing table (such as FAT does) Size of Clusters range from 512 bytes to 64 kilobytes

Directory

a pointer to the root directory and pointers to all directories on the list.

Partition

a section of the hard disk that holds a file system. Each one is divided into tracks, cylinders and sectors when the partition is formatted

Inode

an array of data structures, one per file, telling all about the file.

super block

contains all the key parameters, such as magic number (file system type), number of blocks, and so on.

Journaling File System (JFS)

is a filesystem that maintains a special file called a journal that is used to repair any inconsistencies that occur as the result of an improper shutdown of a computer. Such shutdowns are usually due to an interruption of the power supply or to a software problem that cannot be resolved without a rebooting.

Unix file system

is the large, all-inclusive structure that contains every file and every directory in the entire system. Created by connecting the smaller "device file systems" into one large structure

BIOS

is the program a personal computer's microprocessor uses to get the computer system started after you turn it on. It also manages data flow between the computer's operating system and attached devices such as the hard disk , video adapter , keyboard , mouse , and printer .

file system

method to organize and store information on a system, which includes namespace, API, security model and implementation

Device file system.

smaller, individual files system that resides on various storage devices.

Free space management

usually a bitmap of free space of linked links etc.