ReiserFS is a general-purpose, journaled computer file system formerly designed and implemented by a team at Namesys led by Hans Reiser. ReiserFS is currently supported on Linux licensed as GPLv2. Introduced in version 2.4.1 of the Linux kernel, it was the first journaling file system to be included in the standard kernel. ReiserFS is the default file system on the Elive, Xandros, Linspire, and YOPER Linux distributions. ReiserFS was the default file system in Novell's SUSE Linux Enterprise until Novell decided to move to ext3 on October 12, 2006 for future releases.
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 much free space and another nearly totally allocated.
In the maintenance of file systems, defragmentation is a process that reduces the amount 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 (fragments). 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 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.
In computing, a hard link is a directory entry that associates a name with a file on a file system. All directory-based file systems must have at least one hard link giving the original name for each file. The term “hard link” is usually only used in file systems that allow more than one hard link for the same file.
PartitionMagic is a utility software for hard disk drive partitioning originally made by PowerQuest, but now owned by Symantec. As of December 8, 2009, the Symantec website stated that they no longer offer Partition Magic. The program runs on Microsoft Windows operating systems including Windows 2000 and Windows XP, but the application is incompatible with Windows Vista and later versions. A bootable disk for partitioning drives must be used instead. The utility can also be run from a bootable CD-ROM and enables creation and modification of partitions. Existing partitions can be resized without loss of data.
In computing, a file system or filesystem controls how data is stored and retrieved. Without a file system, information placed in a storage medium would be one large body of data with no way to tell where one piece of information stops and the next begins. By separating the data into pieces and giving each piece a name, the information is easily isolated and identified. Taking its name from the way paper-based information systems are named, each group of data is called a "file". The structure and logic rules used to manage the groups of information and their names is called a "file system".
An extended boot record (EBR), or extended partition boot record (EPBR), is a descriptor for a logical partition under the common DOS disk drive partitioning system. In that system, when one partition record entry in the master boot record (MBR) is designated an extended partition, then that partition can be subdivided into a number of logical partitions. The actual structure of that extended partition is described by one or more EBRs, which are located inside the extended partition. The first EBR will always be located on the very first sector of the extended partition.
Enterprise Volume Management System (EVMS) is a flexible, integrated volume management software used to manage storage systems under Linux.
TestDisk is a free and open-source data recovery utility. It is primarily designed to help recover lost data storage partitions and/or make non-booting disks bootable again when these symptoms are caused by faulty software, certain types of viruses or human error .
TestDisk can be used to collect detailed information about a corrupted drive, which can then be sent to a technician for further analysis.
The following tables compare general and technical information for a number of file systems.
The ext4 or fourth extended filesystem 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.
dm-crypt is a transparent disk encryption subsystem in Linux kernel versions 2.6 and later and in DragonFly BSD. It is part of the device mapper infrastructure, and uses cryptographic routines from the kernel's Crypto API. Unlike its predecessor cryptoloop, dm-crypt was designed to support advanced modes of operation, such as XTS, LRW and ESSIV, in order to avoid watermarking attacks. In addition to that, dm-crypt also addresses some reliability problems of cryptoloop.
libguestfs is a C library and a set of tools for accessing and modifying virtual disk images used in platform virtualization. The tools can be used for viewing and editing virtual machines (VMs) managed by libvirt and files inside VMs, scripting changes to VMs, creating VMs, and much else besides.
Ext2Fsd is a free Installable File System driver written in C for the Microsoft Windows operating system family. It facilitates read and write access to the ext2, ext3 and ext4 file systems.
