ext2, or second extended file system, is a file system for the Linux kernel. It was initially designed by French software developer Rémy Card as a replacement for the extended file system (ext). Having been designed according to the same principles as the Berkeley Fast File System from BSD, it was the first commercial-grade filesystem for Linux.
ext3, or third extended filesystem, is a journaled file system that is commonly used by the Linux kernel. It used to be the default file system for many popular Linux distributions. Stephen Tweedie first revealed that he was working on extending ext2 in Journaling the Linux ext2fs Filesystem in a 1998 paper, and later in a February 1999 kernel mailing list posting. The filesystem was merged with the mainline Linux kernel in November 2001 from 2.4.15 onward. Its main advantage over ext2 is journaling, which improves reliability and eliminates the need to check the file system after an unclean shutdown. Its successor is ext4.
Disk partitioning or disk slicing is the creation of one or more regions on secondary storage, so that each region can be managed separately. These regions are called partitions. It is typically the first step of preparing a newly installed disk, before any file system is created. The disk stores the information about the partitions' locations and sizes in an area known as the partition table that the operating system reads before any other part of the disk. Each partition then appears to the operating system as a distinct "logical" disk that uses part of the actual disk. System administrators use a program called a partition editor to create, resize, delete, and manipulate the partitions. Partitioning allows the use of different filesystems to be installed for different kinds of files. Separating user data from system data can prevent the system partition from becoming full and rendering the system unusable. Partitioning can also make backing up easier. A disadvantage is that it can be difficult to properly size partitions, resulting in having one partition with too much free space and another nearly totally allocated.
In the maintenance of file systems, defragmentation is a process that reduces the degree of fragmentation. It does this by physically organizing the contents of the mass storage device used to store files into the smallest number of contiguous regions. It also attempts to create larger regions of free space using compaction to impede the return of fragmentation. Some defragmentation utilities try to keep smaller files within a single directory together, as they are often accessed in sequence.
Multi-booting is the act of installing multiple operating systems on a single computer, and being able to choose which one to boot. The term dual-booting refers to the common configuration of specifically two operating systems. Multi-booting may require a custom boot loader.
GHOST, now Symantec™ GHOST Solution Suite (GSS) for enterprise, is a disk cloning and backup tool originally developed by Murray Haszard in 1995 for Binary Research. The technology was acquired in 1998 by Symantec.
The Installable File System (IFS) is a filesystem API in MS-DOS/PC DOS 4.x, IBM OS/2 and Microsoft Windows that enables the operating system to recognize and load drivers for file systems.
fstab is a system file commonly found in the directory /etc on Unix and Unix-like computer systems. In Linux, it is part of the util-linux package. The fstab file typically lists all available disk partitions and other types of file systems and data sources that may not necessarily be disk-based, and indicates how they are to be initialized or otherwise integrated into the larger file system structure.
In computing, a file system or filesystem is a method and data structure that the operating system uses to control how data is stored and retrieved. Without a file system, data placed in a storage medium would be one large body of data with no way to tell where one piece of data stopped and the next began, or where any piece of data was located when it was time to retrieve it. By separating the data into pieces and giving each piece a name, the data are easily isolated and identified. Taking its name from the way a paper-based data management system is named, each group of data is called a "file". The structure and logic rules used to manage the groups of data and their names is called a "file system."
The USB mass storage device class is a set of computing communications protocols, specifically a USB Device Class, defined by the USB Implementers Forum that makes a USB device accessible to a host computing device and enables file transfers between the host and the USB device. To a host, the USB device acts as an external hard drive; the protocol set interfaces with a number of storage devices.
Undeletion is a feature for restoring computer files which have been removed from a file system by file deletion. Deleted data can be recovered on many file systems, but not all file systems provide an undeletion feature. Recovering data without an undeletion facility is usually called data recovery, rather than undeletion. Undeletion can both help prevent users from accidentally losing data, or can pose a computer security risk, since users may not be aware that deleted files remain accessible.
GParted is a GTK front-end to GNU Parted and an official GNOME partition-editing application. GParted is used for creating, deleting, resizing, moving, checking, and copying disk partitions and their file systems. This is useful for creating space for new operating systems, reorganizing disk usage, copying data residing on hard disks, and mirroring one partition with another. It can also be used to format a USB drive.
The following tables compare general and technical information for a number of file systems.
e2fsprogs is a set of utilities for maintaining the ext2, ext3 and ext4 file systems. Since those file systems are often the default for Linux distributions, it is commonly considered to be essential software.
ext4 is a journaling file system for Linux, developed as the successor to ext3.
Partimage is a disk cloning utility for Linux/UNIX environments. Partimage can save partitions in many formats to a disk image. Utilities such as Partimage are useful in a number of situations which are commonly encountered by network administrators as well as advanced computer users who maintain their own systems. The last stable release was in 2010; since then, one of Partimage's authors has worked on FSArchiver, which has broader functionality than Partimage.
In computer operating systems, mkfs is a command used to format a block storage device with a specific file system. The command is part of Unix and Unix-like operating systems. In Unix, a block storage device must be formatted with a file system before it can be mounted and accessed through the operating system's filesystem hierarchy.
Recuva is an undeletion program for Windows, developed by Piriform Software. It is able to undelete files that have been marked as deleted; the operating system marks the areas of the disk in which they were stored as free space. Recuva can recover files deleted from internal and external hard disk drives, USB flash drives, memory cards, portable media players or all random-access storage mediums with a supported file system. Preview thumbnails of intact photos can be displayed in grid view mode and in the side bar.
Partclone is a partition clone and restore tool. It provides utilities to back up and restore partitions and is designed for higher compatibility of the file system library. It is developed by the NCHC Free Software Labs in Taiwan. It is the default backup application in Clonezilla, FOG from version 1.00 and Redo Backup and Recovery which is simply a front end to partclone. It supports many file systems and has good performance, as it skips portions of the file system marked as free space.
Partition-Saving is a disk imaging utility for Linux, Windows and DOS environments that can save disk partitions in one of the several supported disk image formats.
