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44-420: XFS excels in the execution of parallel input/output (I/O) operations due to its design, which is based on allocation groups (a type of subdivision of the physical volumes in which XFS is used- also shortened to AGs ). Because of this, XFS enables extreme scalability of I/O threads, file system bandwidth, and size of files and of the file system itself when spanning multiple physical storage devices. XFS ensures

88-402: A 64-bit nanosecond counter instead of the traditional 32-bit seconds counter. This postpones the previous Year 2038 problem until the year 2486. It also introduced metadata checksums. The Gentoo Handbook, Gentoo Linux 's official installation manual, has recommended XFS as the "all-purpose all-platform filesystem" since 28 Jun 2023, succeeding Ext4 . XFS is a 64-bit file system and supports

132-454: A decrease in performance speed. In the event of a system crash, file system operations which occurred immediately prior to the crash can be reapplied and completed as recorded in the journal, which is how data stored in XFS file systems remain consistent. Recovery is performed automatically the first time the file system is mounted after the crash. The speed of recovery is independent of the size of

176-418: A direct I/O implementation that allows non-cached I/O operations to be applied directly to the userspace. Data is transferred between the buffer of the application and the disk using DMA , which allows access to the full I/O bandwidth of the underlying disk devices. XFS does not yet provide direct support for snapshots, as it currently expects the snapshot process to be implemented by the volume manager. Taking

220-576: A fee as part of Red Hat's "scalable file system add-on". Oracle Linux 6, released in 2011, also includes an option for using XFS. RHEL 7.0, released in June 2014, uses XFS as its default file system, including support for using XFS for the /boot partition, which previously was not practical due to bugs in the GRUB bootloader. Linux kernel 4.8 in August 2016 added a new feature, "reverse mapping". This

264-422: A mathematical function In economics, a factor of production , a resource employed to produce goods and services Advice (opinion) Impute (disambiguation) Output (disambiguation) Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with the title Input . If an internal link led you here, you may wish to change the link to point directly to

308-505: A maximum file system size of 8 exbibytes minus one byte (2 − 1 bytes), but limitations imposed by the host operating system can decrease this limit. 32-bit Linux systems limit the size of both the file and file system to 16 tebibytes . In modern computing, journaling is a capability which ensures consistency of data in the file system, despite any power outages or system crash that may occur. XFS provides journaling for file system metadata, where file system updates are first written to

352-402: A number of name/value pairs attached to a file. Names are nul-terminated printable character strings which are up to 256 bytes in length, while their associated values can contain up to 64  KB of binary data. They are further subdivided into two namespaces: root and user . Extended attributes stored in the root namespace can be modified only by the superuser, while attributes in

396-490: A serial journal before the actual disk blocks are updated. The journal is a circular buffer of disk blocks that is not read in normal file system operation. The XFS journal can be stored within the data section of the file system (as an internal log), or on a separate device to minimize disk contention. In XFS, the journal primarily contains entries that describe the portions of the disk blocks changed by filesystem operations. Journal updates are performed asynchronously to avoid

440-468: A small block size would typically maximize capacity, but for a system dealing mainly with large files, a larger block size can provide a performance efficiency advantage. XFS makes use of lazy evaluation techniques for file allocation. When a file is written to the buffer cache, rather than allocating extents for the data, XFS simply reserves the appropriate number of file system blocks for the data held in memory. The actual block allocation occurs only when

484-613: A snapshot of an XFS filesystem involves temporarily halting I/O to the filesystem using the xfs_freeze utility, having the volume manager perform the actual snapshot, and then resuming I/O to continue with normal operations. The snapshot can then be mounted read-only for backup purposes. Releases of XFS in IRIX incorporated an integrated volume manager called XLV. This volume manager has not been ported to Linux, and XFS works with standard LVM in Linux systems instead. In recent Linux kernels,

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528-513: Is a journaling file system for Linux , developed as the successor to ext3 . ext4 was initially a series of backward-compatible extensions to ext3, many of them originally developed by Cluster File Systems for the Lustre file system between 2003 and 2006, meant to extend storage limits and add other performance improvements. However, other Linux kernel developers opposed accepting extensions to ext3 for stability reasons, and proposed to fork

572-552: Is a program replacing the contents of a file without forcing a write to the disk with fsync . There are two common ways of replacing the contents of a file on Unix systems: Using fsync() more often to reduce the risk for ext4 could lead to performance penalties on ext3 filesystems mounted with the data=ordered flag (the default on most Linux distributions). Given that both file systems will be in use for some time, this complicates matters for end-user application developers. In response, ext4 in Linux kernels 2.6.30 and newer detect

616-466: Is the default file system for many Linux distributions including Debian and Ubuntu . In 2008, the principal developer of the ext3 and ext4 file systems, Theodore Ts'o , stated that although ext4 has improved features, it is not a major advance, it uses old technology, and is a stop-gap. Ts'o believes that Btrfs is the better direction because "it offers improvements in scalability, reliability, and ease of management". Btrfs also has "a number of

660-470: Is the foundation for a large set of planned features: snapshots , copy-on-write (COW) data, data deduplication , reflink copies, online data and metadata scrubbing , highly accurate reporting of data loss or bad sectors, and significantly improved reconstruction of damaged or corrupted filesystems. This work required changes to XFS's on-disk format. Linux kernel 5.10, released in December 2020, included

704-427: Is to be created on a striped RAID array, a stripe unit can be specified when the file system is created. This maximizes throughput by ensuring that data allocations, inode allocations and the internal log (the journal) are aligned with the stripe unit. Blocks used in files stored on XFS file systems are managed with variable length extents where one extent describes one or more contiguous blocks. This can shorten

748-408: Is to write and use software that does fsync() when it needs to. Performance problems can be minimized by limiting crucial disk writes that need fsync() to occur less frequently. Linux kernel Virtual File System is a subsystem or layer inside of the Linux kernel. It is the result of an attempt to integrate multiple file systems into an orderly single structure. The key idea, which dates back to

792-521: The xfs_freeze functionality is implemented in the VFS layer, and is executed automatically when the Volume Manager's snapshot functionality is invoked. This was once a valuable advantage as the ext3 file system could not be suspended and the volume manager was unable to create a consistent "hot" snapshot to back up a heavily busy database. Fortunately this is no longer the case. Since Linux 2.6.29,

836-509: The xfs_growfs utility to perform online expansion of XFS file systems. XFS filesystems can be grown so long as there is remaining unallocated space on the device holding the filesystem. This feature is typically used in conjunction with volume management, as otherwise the partition holding the filesystem will need enlarging separately. XFS implemented the DMAPI interface to support Hierarchical Storage Management in IRIX. As of October 2010,

880-425: The Linux 2.6.28 source code repositories, denoting the end of the development phase and recommending ext4 adoption. Kernel 2.6.28, containing the ext4 filesystem, was finally released on 25 December 2008. On 15 January 2010, Google announced that it would upgrade its storage infrastructure from ext2 to ext4. On 14 December 2010, Google also announced it would use ext4, instead of YAFFS , on Android 2.3 . ext4

924-512: The Linux implementation of XFS supported the required on-disk metadata for DMAPI implementation, but the kernel support was reportedly not usable. For some time, SGI hosted a kernel tree which included the DMAPI hooks, but this support has not been adequately maintained, although kernel developers have stated an intention to bring this support up to date. The XFS guaranteed-rate I/O system provides an API that allows applications to reserve bandwidth to

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968-612: The Linux kernel came through patches from SGI. It merged into the Linux kernel mainline for the 2.6 series, and separately merged in February 2004 into the 2.4 series in version 2.4.25, making XFS almost universally available on Linux systems. Gentoo Linux became the first Linux distribution to introduce an option for XFS as the default filesystem in mid-2002. FreeBSD added read-only support for XFS in December 2005, and in June 2006 introduced experimental write support. However, this

1012-657: The act of entering data into a computer or data processing system Information , any data entered into a computer or data processing system Input device Input method Input port (disambiguation) Input/output (I/O), in computing Other [ edit ] Input (talk show) Input (typeface) International Public Television Screening Conference (INPUT), an international public television organization Input (online magazine) , an online technology and culture magazine owned by Bustle Digital Group See also [ edit ] All pages with titles containing Input Independent variable in

1056-490: The consistency of data by employing metadata journaling and supporting write barriers . Space allocation is performed via extents with data structures stored in B+ trees , improving the overall performance of the file system, especially when handling large files. Delayed allocation assists in the prevention of file system fragmentation; online defragmentation is also supported. Silicon Graphics began development of XFS ("X"

1100-410: The data is finally flushed to disk. This improves the chance that the file will be written in a contiguous group of blocks, reducing fragmentation problems and increasing performance. XFS provides a 64-bit sparse address space for each file, which allows both for very large file sizes, and for "holes" within files in which no disk space is allocated. As the file system uses an extent map for each file,

1144-406: The file allocation map size is kept small. Where the size of the allocation map is too large for it to be stored within the inode, the map is moved into a B+ tree which allows for rapid access to data anywhere in the 64-bit address space provided for the file. XFS provides multiple data streams for files; this is made possible by its implementation of extended attributes . These allow the storage of

1188-454: The file system, instead depending on the amount of file system operations to be reapplied. XFS file systems are internally partitioned into allocation groups , which are equally sized linear regions within the file system. Files and directories can span allocation groups. Each allocation group manages its own inodes and free space separately, providing scalability and parallelism so multiple threads and processes can perform I/O operations on

1232-434: The file systems ext3, ext4 , GFS2 and JFS have the freeze feature as well. Although the extent-based nature of XFS and the delayed allocation strategy it uses significantly improves the file system's resistance to fragmentation problems, XFS provides a filesystem defragmentation utility ( xfs_fsr , short for XFS filesystem reorganizer) that can defragment the files on a mounted and active XFS filesystem. XFS provides

1276-425: The file-system journal. Because delayed allocation changes the behavior that programmers have been relying on with ext3, the feature poses some additional risk of data loss in cases where the system crashes or loses power before all of the data has been written to disk. Due to this, ext4 in kernel versions 2.6.30 and later automatically handles these cases as ext3 does. The typical scenario in which this might occur

1320-402: The filesystem. XFS dynamically calculates the performance available from the underlying storage devices, and will reserve bandwidth sufficient to meet the requested performance for a specified time. This is a feature unique to the XFS file system. Guaranteed rates can be "hard" or "soft", representing a trade off between reliability and performance; however, XFS will only allow "hard" guarantees if

1364-564: The intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Input&oldid=1184557364 " Category : Disambiguation pages Hidden categories: Short description is different from Wikidata All article disambiguation pages All disambiguation pages Ext4 EBD0A0A2-B9E5-4433-87C0-68B6B72699C7 : GPT Windows BDP . 0FC63DAF-8483-4772-8E79-3D69D8477DE4 : GPT Linux filesystem data. 933AC7E1-2EB4-4F13-B844-0E14E2AEF915 : GPT /home partition. ext4 ( fourth extended filesystem )

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1408-467: The list of blocks considerably, compared to file systems that list all blocks used by a file individually. Block-oriented file systems manage space allocation with one or more block-oriented bitmaps; in XFS, these structures are replaced with an extent oriented structure consisting of a pair of B+ trees for each file system allocation group. One of the B+ trees is indexed by the length of the free extents, while

1452-511: The new on-disk format XFS v5. This was a hard break, since the deprecated XFS v4 can not be converted to XFS v5. Data on partitions formatted with XFS v4 has to be backed up to another partition or media in order to restore it after formatting the old partition with XFS v5, which completely wipes all data on it. The support for XFS v4 will be removed from the Linux kernel in September 2030. XFS v5 introduced "bigtime", to store inode timestamps as

1496-608: The occurrence of these common cases and force the files to be allocated immediately. For a small cost in performance, this provides semantics similar to ext3 ordered mode and increases the chance that either version of the file will survive the crash. This new behavior is enabled by default, but can be disabled with the "noauto_da_alloc" mount option. The new patches have become part of the mainline kernel 2.6.30, but various distributions chose to backport them to 2.6.28 or 2.6.29. These patches don't completely prevent potential data loss or help at all with new files. The only way to be safe

1540-454: The other is indexed by the starting block of the free extents. This dual indexing scheme allows for the highly efficient allocation of free extents for file system operations. The file system block size represents the minimum allocation unit. XFS allows file systems to be created with block sizes ranging between 512 bytes and 64 KB, allowing the file system to be tuned for the expected degree of usage. When many small files are expected,

1584-438: The pioneering work done by Sun Microsystems employees in 1986, is to abstract out that part of the file system that is common to all file systems and put that code in a separate layer that calls the underlying concrete file systems to actually manage the data. All system calls related to files (or pseudo files) are directed to the Linux kernel Virtual File System for initial processing. These calls, coming from user processes, are

1628-405: The same design ideas that reiser3 / 4 had". However, ext4 has continued to gain new features such as file encryption and metadata checksums. The ext4 file system does not honor the "secure deletion" file attribute , which is supposed to cause overwriting of files upon deletion. A patch to implement secure deletion was proposed in 2011, but did not solve the problem of sensitive data ending up in

1672-433: The same file system simultaneously. This architecture helps to optimize parallel I/O performance on systems with multiple processors and/or cores, as metadata updates can also be parallelized. The internal partitioning provided by allocation groups can be especially beneficial when the file system spans multiple physical devices, allowing optimal usage of throughput of the underlying storage components. If an XFS file system

1716-431: The source code of ext3, rename it as ext4, and perform all the development there, without affecting existing ext3 users. This proposal was accepted, and on 28 June 2006, Theodore Ts'o , the ext3 maintainer, announced the new plan of development for ext4. A preliminary development version of ext4 was included in version 2.6.19 of the Linux kernel. On 11 October 2008, the patches that mark ext4 as stable code were merged in

1760-409: The standard POSIX calls, such as open , read , write , lseek , etc. Although designed for and primarily used with Linux, an ext4 file system can be accessed via other operating systems via interoperability tools. Windows provides access via its Windows Subsystem for Linux (WSL) technology. Specifically, the second major version, WSL 2, is the first version with ext4 support. It

1804-508: The underlying storage subsystem supports it. This facility is used mostly for real-time applications, such as video streaming. Guaranteed-rate I/O was only supported under IRIX , and required special hardware for that purpose. Input [REDACTED] Look up input in Wiktionary, the free dictionary. Input may refer to: Computing [ edit ] Input (computer science) ,

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1848-566: The user namespace can be modified by any user with permission to write to the file. Extended attributes can be attached to any kind of XFS inode, including symbolic links, device nodes, directories, etc. The attr utility can be used to manipulate extended attributes from the command line, and the xfsdump and xfsrestore utilities are aware of extended attributes, and will back up and restore their contents. Many other backup systems do not support working with extended attributes. For applications requiring high throughput to disk, XFS provides

1892-524: Was intended only as an aid in migration from Linux, not as a "main" file system. FreeBSD 10 removed support for XFS. In 2009, version 5.4 of 64-bit Red Hat Enterprise Linux (RHEL) Linux distribution contained the necessary kernel support for the creation and usage of XFS file systems, but lacked the corresponding command-line tools. The tools available from CentOS could operate for that purpose, and Red Hat also provided them to RHEL customers on request. RHEL 6.0, released in 2010, includes XFS support for

1936-541: Was meant to be filled in later but never was) in 1993 for its UNIX System V based IRIX operating system. The file system was released under the GNU General Public License (GPL) in May 1999. A team led by Steve Lord at SGI ported XFS to Linux, and first support by a Linux distribution came in 2001. This support gradually became available in almost all Linux distributions. Initial support for XFS in

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