The Oracle Cluster File System (OCFS, in its second version OCFS2) is a
shared disk file system
A clustered file system is a file system which is shared by being simultaneously mounted on multiple servers. There are several approaches to clustering, most of which do not employ a clustered file system (only direct attached storage for ...
developed by
Oracle Corporation and released under the
GNU General Public License
The GNU General Public License (GNU GPL or simply GPL) is a series of widely used free software licenses that guarantee end users the four freedoms to run, study, share, and modify the software. The license was the first copyleft for general ...
.
The first version of OCFS was developed with the main focus to accommodate Oracle's
database management system that used
cluster computing
A computer cluster is a set of computers that work together so that they can be viewed as a single system. Unlike grid computers, computer clusters have each node set to perform the same task, controlled and scheduled by software.
The compo ...
. Because of that it was not a
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 ...
-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 in late 2008, more features were included into ocfs2, such as
access control list
In computer security, an access-control list (ACL) is a list of permissions associated with a system resource (object). An ACL specifies which users or system processes are granted access to objects, as well as what operations are allowed on gi ...
s and quotas.
OCFS2 used a
distributed lock manager
Operating systems use lock managers to organise and serialise the access to resources. A distributed lock manager (DLM) runs in every machine in a cluster, with an identical copy of a cluster-wide lock database. In this way a DLM provides software ...
which resembles the
OpenVMS DLM but is much simpler.
Oracle announced version 1.6 in November 2010 which included a
copy on write
Copy-on-write (COW), sometimes referred to as implicit sharing or shadowing, is a resource-management technique used in computer programming to efficiently implement a "duplicate" or "copy" operation on modifiable resources. If a resource is dupl ...
feature called reflink.
See also
*
GlusterFS
Gluster Inc. (formerly known as Z RESEARCH) was a software company that provided an open source platform for scale-out public and private cloud storage. The company was privately funded and headquartered in Sunnyvale, California, with an enginee ...
*
GFS2
In computing, the Global File System 2 or GFS2 is a shared-disk file system for Linux computer clusters. GFS2 allows all members of a cluster to have direct concurrent access to the same shared block storage, in contrast to distributed file sy ...
*
General Parallel File System
GPFS (General Parallel File System, brand name IBM Spectrum Scale) is high-performance clustered file system software developed by IBM. It can be deployed in shared-disk or shared-nothing distributed parallel modes, or a combination of these. I ...
(GPFS)
*
List of file systems
The following lists identify, characterize, and link to more thorough information on Computer file systems.
Many older operating systems support only their one "native" file system, which does not bear any name apart from the name of the operating ...
*
Lustre (file system)
Lustre is a type of parallel distributed file system, generally used for large-scale cluster computing. The name Lustre is a portmanteau word derived from Linux and cluster. Lustre file system software is available under the GNU General Publ ...
*
MooseFS
*
QFS
QFS (Quick File System) is a filesystem from Oracle. 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.
Features
QFS ...
Notes and references
External links
OCFS2project page
OCFSproject page
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{{DEFAULTSORT:Ocfs
Shared disk file systems
Oracle software
Distributed file systems supported by the Linux kernel