VERITAS File System
Full nameVERITAS File System
Introduced1991; 33 years ago (1991)
Structures
Directory contentsextensible hash
Limits
Max volume size277 bytes (128 ZiB)
Max file size263 bytes (8 EiB)
Max filename length256 bytes
Features
Forksyes
AttributesExtended file attributes
File system
permissions
Unix permissions, ACL
Transparent
compression
No
Transparent
encryption
No
Other
Supported
operating systems
Linux, Solaris, HP-UX, AIX, SINIX, UnixWare

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.[1] Through an OEM agreement, VxFS is used as the primary filesystem of the HP-UX operating system. With on-line defragmentation and resize support turned on via license, it is known as OnlineJFS.[2] It is also supported on AIX, Linux, Solaris, OpenSolaris, SINIX/Reliant UNIX, UnixWare and SCO OpenServer.[citation needed] VxFS was originally developed for AT&T's Unix System Laboratories. 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.[3] 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.[4] 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 in 1990.[5] Other sources agree that the product was first released in 1991.[6][7]

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.[citation needed]

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.

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 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

References

  1. ^ "Incrementally restoring a mass storage device to a prior state". 2005-03-22. Archived from the original on 2008-03-09. Retrieved 2007-11-21.
  2. ^ Donna Yobs (2000-04-10). "Post in the veritas-vx mailing list explaining the differences between JFS and OJFS". Archived from the original on 2008-03-09. Retrieved 2007-11-21.
  3. ^ "VERITAS Foundation Suite and Foundation Suite HA 3.5" (PDF). VERITAS. Archived from the original (PDF) on 2003-10-25. Retrieved 2007-11-21.
  4. ^ "6th International Linux Kongress". 1999-09-09. Retrieved 2007-11-21.
  5. ^ Dan Koren (1999-06-01). "Re: XFS and journalling filesystems". LKML.org. Retrieved 2007-11-21.
  6. ^ "Next-Gen File Systems — File under 'futuristic': An overview of the technologies and players — The Heavy Hitters: Veritas". Byte and Switch. 2002-11-14. Archived from the original on 2008-03-09. Retrieved 2007-11-21.
  7. ^ "VERITAS Celebrates 15 Years - Next Big Focus: Grid Computing". SYS-CON. 2004-09-14. Archived from the original on 2008-03-11. Retrieved 2007-11-21.
  8. ^ a b "Veritas File Systems with Disk Layout Version 4 or Version 5 Cannot be Mounted or Upgraded with Veritas File System Release 5.1".