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{{Infobox filesystem
{{Infobox filesystem
| name = OCFS2
| name = OCFS2
| full_name = Oracle Cluster File System
| full_name = Oracle Cluster file System
| developer = [[Oracle Corporation]]
| developer = [[Oracle Corporation]]
| introduction_os = [[Linux]] 2.6.16
| introduction_os = [[Linux]] 2.6.16
| introduction_date = [[March 2006]]
| introduction_date = March 2006
| partition_id =
| partition_id =
| directory_struct =
| directory_struct =
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| max_filename_size = 255 bytes
| max_filename_size = 255 bytes
| max_files_no =
| max_files_no =
| max_volume_size = 4 PB (OCFS2)<ref name="JBD" />
| max_volume_size= 4 PB (OCFS2)<ref name="JBD">Limited to 16TiB before 2.6.28 since it used the Linux [[Journaling block device|JBD]]. JBD2 removes the limit.</ref>
| max_file_size = 4 PB (OCFS2)<ref name="JBD">Currently limited to 16TiB since it uses the Linux [[Journaling block device|JBD]]</ref>
| max_file_size= 4 PB (OCFS2)<ref name="JBD"/>
| filename_character_set = All bytes except NULL and '/'
| filename_character_set = All bytes except [[Null character|NUL]] and '/'
| dates_recorded = modification (mtime), attribute modification (ctime), access (atime)
| dates_recorded = modification (mtime), attribute modification (ctime), access (atime)
| date_range =
| date_range =
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| encryption = No
| encryption = No
| single_instance_storage = No
| single_instance_storage = No
| copy_on_write = Yes
| OS = Linux
| OS = Linux
}}
}}


'''OCFS''' stands for '''Oracle Cluster File System'''. It is a [[shared disk file system]] developed by [[Oracle Corporation]] and released under the [[GNU General Public License]].
The Oracle Cluster File System ('''OCFS''', in its second version '''OCFS2''') is a [[shared disk file system]] developed by [[Oracle Corporation]] and released under the [[GNU General Public License]].
⚫
The first version of OCFS was developed with the main focus to accommodate Oracle's [[database management system]] that used [[cluster computing]]. Because of that it was not a [[POSIX]]-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)|Linux kernel]]. Initially, it was marked as "experimental" ([[Software release life cycle#Alpha|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]]s and quotas.<ref>{{cite web |title= Ocfs2 patches for merge window batch 1/3 |author= Mark Fasheh |date= December 19, 2008 |work= Linux Kernel Mailing List |url= https://lkml.org/lkml/2008/12/19/280 |access-date= October 24, 2016 }}</ref><ref>{{cite web |title= Ocfs2 patches for merge window batch 2/3 |author= Mark Fasheh |date= December 22, 2008 |work= Linux Kernel Mailing List |url= https://lkml.org/lkml/2008/12/22/213 |access-date= October 24, 2016 }}</ref>
⚫
The first version of OCFS was developed with the main focus to accommodate oracle database files for [[clustered database]]s. Because of that it was not an [[POSIX]] compliant file system. With version 2 the POSIX features were included.


⚫
OCFS2 used a [[distributed lock manager]] which resembles the [[OpenVMS]] DLM but is much simpler.<ref>{{cite web |url= https://lwn.net/Articles/137278 |title= The OCFS2 filesystem |work= [[LWN.net]] |author= Jonathan Corbet |date= May 24, 2005 |access-date= October 24, 2016 }}</ref>
OCFS2 (version 2) was integrated into the version 2.6.16 of [[Linux (kernel)|Linux kernel]]. Initially, it was marked as "experimental" ([[Development stage#Alpha|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.<ref>http://thread.gmane.org/gmane.linux.kernel/775637</ref>
Oracle announced version 1.6 in November 2010 which included a [[copy on write]] feature called reflink.<ref>{{Cite web |title= What's new in Oracle Linux Part 1: OCFS2 1.6 REFLINKs |author= John Margaglione |publisher= Oracle |date= November 30, 2010 |url= https://blogs.oracle.com/devpartner/entry/whats_new_in_oracle_linux |archive-url= https://web.archive.org/web/20170510113950/https://blogs.oracle.com/devpartner/entry/whats_new_in_oracle_linux |url-status= dead |archive-date= May 10, 2017 |access-date= May 10, 2017 }}</ref>

⚫
OCFS2 uses a [[distributed lock manager]] which resembles the [[OpenVMS]] DLM but is much simpler.<ref>http://lwn.net/Articles/137278/</ref>


==See also==
==See also==
{{Portal|Free software}}
{{Portal|Free and open-source software}}
* [[GlusterFS]]
⚫
* [[Global File System]] (GFS)
* [[GFS2]]
* [[General Parallel File System]] (GPFS)
* [[General Parallel File System]] (GPFS)
* [[List of file systems]]
* [[List of file systems]]
* [[Lustre (file system)]]
* [[Lustre (file system)]]
⚫
* [[Moose File System|MooseFS]]
* [[QFS]]
* [[QFS]]
* [[Starfish File System|Starfish]]


==Notes and references==
==Notes and references==
Line 47: Line 49:


==External links==
==External links==
* [http://oss.oracle.com/projects/ocfs2/ OCFS2] project page
*[http://oss.oracle.com/projects/ocfs2/ OCFS2] project page
* [http://oss.oracle.com/projects/ocfs/ OCFS] project page
*[http://oss.oracle.com/projects/ocfs/ OCFS] project page
* [http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=blob_plain;f=Documentation/filesystems/ocfs2.txt;hb=HEAD Documentation/filesystems/ocfs2.txt] in the Linux tree
*{{cite web|url=https://www.kernel.org/doc/Documentation/filesystems/ocfs2.txt|title=OCFS2 filesystem|date=2011-08-11}}


{{Filesystem}}
{{Filesystem}}
{{Oracle FOSS}}


{{DEFAULTSORT:Ocfs}}
{{DEFAULTSORT:Ocfs}}
[[Category:Shared disk file systems]]
[[Category:Shared disk file systems]]
[[Category:Oracle software]]
[[Category:Oracle software]]
[[Category:Linux file systems]]
[[Category:Distributed file systems supported by the Linux kernel]]


{{Compu-storage-stub}}

[[de:OCFS2]]
[[ja:OCFS]]
[[pl:OCFS2]]

Latest revision as of 22:11, 28 February 2021

OCFS2
Developer(s)Oracle Corporation
Full nameOracle Cluster file System
IntroducedMarch 2006 with Linux 2.6.16
Limits
Max volume size4 PB (OCFS2)[1]
Max file size4 PB (OCFS2)[1]
Max filename length255 bytes
Allowed filename
characters		All bytes except NUL and '/'
Features
Dates recordedmodification (mtime), attribute modification (ctime), access (atime)
File system
permissions		Unix permissions, ACLs and arbitrary security attributes (Linux 2.6 and later)
Transparent
compression		No
Transparent
encryption		No
Data deduplicationNo
Copy-on-writeYes
Other
Supported
operating systems		Linux

The Oracle Cluster File System (OCFS, in its second version OCFS2) is a shared disk file system developed by Oracle Corporation and released under the GNU General Public License. The first version of OCFS was developed with the main focus to accommodate Oracle's database management system that used cluster computing. Because of that it was not a POSIX-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 lists and quotas.[2][3]

OCFS2 used a distributed lock manager which resembles the OpenVMS DLM but is much simpler.[4] Oracle announced version 1.6 in November 2010 which included a copy on write feature called reflink.[5]

See also

[edit]

Notes and references

[edit]
  1. ^ a b Limited to 16TiB before 2.6.28 since it used the Linux JBD. JBD2 removes the limit.
  2. ^ Mark Fasheh (December 19, 2008). "Ocfs2 patches for merge window batch 1/3". Linux Kernel Mailing List. Retrieved October 24, 2016.
  3. ^ Mark Fasheh (December 22, 2008). "Ocfs2 patches for merge window batch 2/3". Linux Kernel Mailing List. Retrieved October 24, 2016.
  4. ^ Jonathan Corbet (May 24, 2005). "The OCFS2 filesystem". LWN.net. Retrieved October 24, 2016.
  5. ^ John Margaglione (November 30, 2010). "What's new in Oracle Linux Part 1: OCFS2 1.6 REFLINKs". Oracle. Archived from the original on May 10, 2017. Retrieved May 10, 2017.
[edit]
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