OCFS is a shared disk file system developed by Oracle Corporation

Oracle Corporation

Oracle Corporation is an American multinational computer technology corporation that specializes in developing and marketing hardware systems and enterprise software products – particularly database management systems...

 and released under the GNU General Public License

GNU General Public License

The GNU General Public License is the most widely used free software license, originally written by Richard Stallman for the GNU Project....

.

The first version of OCFS was developed with the main focus to accommodate oracle database files for clustered databases. Because of that it was not a POSIX

POSIX

POSIX , an acronym for "Portable Operating System Interface", is a family of standards specified by the IEEE for maintaining compatibility between operating systems...

 compliant file system. With version 2 the POSIX features were included.

OCFS2 (version 2) was integrated into the version 2.6.16 of Linux kernel. Initially, it was marked as "experimental" (Alpha-test) code. This restriction was removed in Linux version 2.6.19. With kernel version 2.6.29 more features have been included into ocfs2 especially access control lists and quota.

OCFS2 uses a distributed lock manager

Distributed lock manager

A distributed lock manager provides distributed software applications with a means to synchronize their accesses to shared resources....

 which resembles the OpenVMS

OpenVMS

OpenVMS , previously known as VAX-11/VMS, VAX/VMS or VMS, is a computer server operating system that runs on VAX, Alpha and Itanium-based families of computers. Contrary to what its name suggests, OpenVMS is not open source software; however, the source listings are available for purchase...

 DLM but is much simpler.

See also

• GlusterFS
  GlusterFS
  GlusterFS is a scale-out NAS file system developed by Gluster. It aggregates various storage servers over Ethernet or Infiniband RDMA interconnect into one large parallel network file system. GlusterFS is based on a stackable user space design without compromising performance. It has found a...
  
  
• Global File System
  Global File System
  In computing, the Global File System is a shared disk file system for Linux computer clusters. This is not to be confused with the Google File System, a proprietary distributed filesystem developed by Google....
  
   (GFS)
• General Parallel File System
  General Parallel File System
  The General Parallel File System is a high-performance shared-disk clustered file system developed by IBM. It is used by some of the supercomputers on the Top 500 List...
  
   (GPFS)
• List of file systems
• Lustre (file system)
  Lustre (file system)
  Lustre is a massively parallel distributed file system, generally used for large scale cluster computing. The name Lustre is a portmanteau word derived from Linux and cluster...
  
  
• QFS
  QFS
  QFS is an open source filesystem from Sun Microsystems. It is tightly integrated with SAM, the Storage and Archive Manager, and hence is often referred to as SAM-QFS. SAM provides the functionality of a Hierarchical Storage Manager....
  
  

External links

• OCFS2 project page
• OCFS project page
• http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=blob;f=Documentation/filesystems/ocfs2.txt;h=7618a287aa41f085e8c166393b99ee31672c2a9e;hb=HEAD in the Linux tree