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The VERITAS File System (or VxFS; called JFS and OnlineJFS in HP-UX) is an extent-based file system. It was originally developed by VERITAS Software. Through an
OEM An original equipment manufacturer (OEM) is generally perceived as a company that produces non-aftermarket parts and equipment that may be marketed by another manufacturer. It is a common industry term recognized and used by many professional or ...
agreement, VxFS is used as the primary filesystem of the HP-UX
operating system An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may also i ...
. With on-line
defragmentation 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 contigu ...
and resize support turned on via license, it is known as ''OnlineJFS''. It is also supported on AIX,
Linux Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, w ...
, Solaris, OpenSolaris, SINIX/Reliant UNIX, UnixWare and
SCO OpenServer Xinuos OpenServer, previously SCO UNIX and SCO Open Desktop (SCO ODT), is a closed source computer operating system developed by Santa Cruz Operation (SCO), later acquired by SCO Group, and now owned by Xinuos. Early versions of OpenServer we ...
. VxFS was originally developed for
AT&T AT&T Inc. is an American multinational telecommunications holding company headquartered at Whitacre Tower in Downtown Dallas, Texas. It is the world's largest telecommunications company by revenue and the third largest provider of mobile te ...
's
Unix System Laboratories Unix System Laboratories (USL), sometimes written UNIX System Laboratories to follow relevant trademark guidelines of the time, was an American software laboratory and product development company that existed from 1989 through 1993. At first wh ...
. VxFS is packaged as a part of the Veritas Storage Foundation (which also includes Veritas Volume Manager).


History

According to the vendor, it was the first commercial
journaling file system A journaling file system is a file system that keeps track of changes not yet committed to the file system's main part by recording the goal of such changes in a data structure known as a " journal", which is usually a circular log. In the even ...
. That claim can be taken in two ways, i.e., the first implementation of a journaling file system in a commercial context, or the first file system available as an unbundled product. Dan Koren is cited as one of the original developers of VxFS. He notes in a mailing list that they "finished release 1.0 one year or so later" after starting development of VxFS under a contract with
AT&T Corporation AT&T Corporation, originally the American Telephone and Telegraph Company, is the subsidiary of AT&T Inc. that provides voice, video, data, and Internet telecommunications and professional services to businesses, consumers, and government agen ...
in 1990. Other sources agree that the product was first released in 1991. As the internet was not widely available in the early 1990s, getting a new file system deployed for Unix-like operating systems was more difficult, so the one- to two-year delay in the release and commercialization of this file system was not unusual.


Version history

The on-disk layout of VxFS is versioned and upgradeable while the file system is mounted. This file system has gone through ten versions. * Version 2 added support for filesets, dynamic inode allocation and ACLs. Layouts 1-3 stopped being supported in VxFS 4.0. * Version 4 added support for storage checkpoints and for Veritas Cluster File System. Version 4 was released in VxFS 3.2.1. Layout version 4 is no longer supported under VxFS 5.1. * Version 5 started support for file systems up to 32
terabyte The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable uni ...
s () in size. Individual files can be up to 2 terabytes in size. Version 5 was introduced in VxFS 3.5 and is no longer supported under VxFS 5.1. * Version 6 added support for file systems and files up to 8
exabyte The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable uni ...
s () in size. Version 6 also introduced support for named streams/resource forks, for multiple underlying volumes, and for file change logs. Version 6 was introduced in VxFS 4.0. * Version 7 extends support for multiple volumes to permit Dynamic Storage Tiering. Dynamic Storage Tiering allows root users to move files among different volumes, allocate files to different volumes at file creation time based on policy, and independently recover volumes, without altering the namespace of the file system. Version 7 was introduced in VxFS 5.0. * Version 8 enables support for file-level snapshots and shared extents. Version 8 was introduced in VxFS 5.1. * Version 9 enables support for file compression, deduplication, and partition directories. Version 9 was introduced in VxFS 6.0. * Version 10 enables support for maxlink, which permits a directory to contain more than 64K subdirectories. Version 10 was introduced in VxFS 6.1.


Parallel access mode

VxFS file system can run in ''single instance mode'' or in a ''parallel access / cluster mode''. The parallel mode allows for multiple servers (also known as cluster nodes) to simultaneously access the same file system. When run in this mode, VxFS is referred to as Veritas Cluster File System. The Cluster File System provides cache coherency and
POSIX The Portable Operating System Interface (POSIX) is a family of standards specified by the IEEE Computer Society for maintaining compatibility between operating systems. POSIX defines both the system- and user-level application programming inter ...
compliance across nodes, so that data changes are atomically seen by all cluster nodes simultaneously. Because Cluster File System shares the same binaries and same on-disk layout as single instance VxFS, moving between cluster and single instance mode is straightforward.


See also

*
Comparison of file systems The following tables compare general and technical information for a number of file systems. General information Limits Metadata Features File capabilities Block capabilities Note that in addition to the below table, blo ...
* Symantec Operations Readiness Tools (SORT)


References


External links


Veritas Services and Operations Readiness Tools (SORT) documentation search

VERITAS Storage Foundation

VxFS Quick Reference

VERITAS Cluster File System

Symantec Operations Readiness Tools
!-- ERR_NAME_NOT_RESOLVED --> (SORT) {{Filesystem 1991 software Disk file systems Shared disk file systems HP software File systems supported by the Linux kernel