The Oracle Cluster File System (OCFS, in its second version OCFS2) is a

shared disk file system A clustered file system (CFS) 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 stor ...

developed by

Oracle Corporation Oracle Corporation is an American Multinational corporation, multinational computer technology company headquartered in Austin, Texas. Co-founded in 1977 in Santa Clara, California, by Larry Ellison, who remains executive chairman, Oracle was ...

and released under the

GNU General Public License The GNU General Public Licenses (GNU GPL or simply GPL) are a series of widely used free software licenses, or ''copyleft'' licenses, that guarantee end users the freedom to run, study, share, or modify the software. The GPL was the first ...

. The first version of OCFS was developed with the main focus to accommodate Oracle's

database management system In computing, a database is an organized collection of data or a type of data store based on the use of a database management system (DBMS), the software that interacts with end users, applications, and the database itself to capture and an ...

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 computing, grid computers, computer clusters have each Node (networking), node set to perform the same task, controlled an ...

. 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 application programming interfaces (APIs), along with comm ...

-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 The Linux kernel is a Free and open-source software, free and open source Unix-like kernel (operating system), kernel that is used in many computer systems worldwide. The kernel was created by Linus Torvalds in 1991 and was soon adopted as the k ...

. 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 or facility). An ACL specifies which users or system processes are granted access to resources, as well as what operations are ...

s and quotas. OCFS2 used a

distributed lock manager A distributed lock manager (DLM) runs in every machine in a cluster, with an identical copy of a cluster-wide lock database. Operating systems use lock managers to organise and serialise the access to resources. In this way a DLM provides software ...

which resembles the

OpenVMS OpenVMS, often referred to as just VMS, is a multi-user, multiprocessing and virtual memory-based operating system. It is designed to support time-sharing, batch processing, transaction processing and workstation applications. Customers using Op ...

DLM but is much simpler. Oracle announced version 1.6 in November 2010 which included a

copy on write Copy may refer to: *Copying or the product of copying (including the plural "copies"); the duplication of information or an artifact **Cut, copy and paste, a method of reproducing text or other data in computing ** File copying **Photocopying, a p ...

feature called reflink.

Notes and references

External links

OCFS2
project page
OCFS
project page * {{DEFAULTSORT:Ocfs Shared disk file systems Oracle software Distributed file systems supported by the Linux kernel

See also

Notes and references

External links