# OCFS2 > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/OCFS2 > Markdown URL: https://mediated.wiki/source/OCFS2.md > Source: https://en.wikipedia.org/wiki/OCFS2 > Source revision: 1345598670 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) Clustered file system This article is about the Oracle Cluster File System. For the New York state agency, see [New York State Office of Children and Family Services](/source/New_York_State_Office_of_Children_and_Family_Services). OCFS2 Developer(s) Oracle Corporation Full name Oracle Cluster file System Introduced March 2006 with Linux 2.6.16 Limits Max volume size 4 PB (OCFS2)[1] Max file size 4 PB (OCFS2)[1] Max filename length 255 bytes Allowed filename characters All bytes except NUL and '/' Features Dates recorded modification (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 deduplication No Copy-on-write Yes Other Supported operating systems Linux The Oracle Cluster File System (**OCFS**, in its second version **OCFS2**) is a [shared disk file system](/source/Shared_disk_file_system) developed by [Oracle Corporation](/source/Oracle_Corporation) and released under the [GNU General Public License](/source/GNU_General_Public_License). The first version of OCFS was developed with the main focus to accommodate Oracle's [database management system](/source/Database_management_system) that used [cluster computing](/source/Cluster_computing). Because of that it was not a [POSIX](/source/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](/source/Linux_(kernel)). Initially, it was marked as "experimental" ([Alpha-test](/source/Software_release_life_cycle#Alpha)) 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](/source/Access_control_list) and quotas.[2][3] OCFS2 used a [distributed lock manager](/source/Distributed_lock_manager) which resembles the [OpenVMS](/source/OpenVMS) DLM but is much simpler.[4] Oracle announced version 1.6 in November 2010 which included a [copy on write](/source/Copy_on_write) feature called reflink.[5] ## See also - [Free and open-source software portal](https://en.wikipedia.org/wiki/Portal:Free_and_open-source_software) - [GlusterFS](/source/GlusterFS) - [GFS2](/source/GFS2) - [General Parallel File System](/source/General_Parallel_File_System) (GPFS) - [List of file systems](/source/List_of_file_systems) - [Lustre (file system)](/source/Lustre_(file_system)) - [MooseFS](/source/Moose_File_System) - [QFS](/source/QFS) ## Notes and references 1. ^ [***a***](#cite_ref-JBD_1-0) [***b***](#cite_ref-JBD_1-1) Limited to 16TiB before 2.6.28 since it used the Linux [JBD](/source/Journaling_block_device). JBD2 removes the limit. 1. **[^](#cite_ref-2)** Mark Fasheh (December 19, 2008). ["Ocfs2 patches for merge window batch 1/3"](https://lkml.org/lkml/2008/12/19/280). *Linux Kernel Mailing List*. Retrieved October 24, 2016. 1. **[^](#cite_ref-3)** Mark Fasheh (December 22, 2008). ["Ocfs2 patches for merge window batch 2/3"](https://lkml.org/lkml/2008/12/22/213). *Linux Kernel Mailing List*. [Archived](https://web.archive.org/web/20161025110813/https://lkml.org/lkml/2008/12/22/213) from the original on October 25, 2016. Retrieved October 24, 2016. 1. **[^](#cite_ref-4)** Jonathan Corbet (May 24, 2005). ["The OCFS2 filesystem"](https://lwn.net/Articles/137278). *[LWN.net](/source/LWN.net)*. Retrieved October 24, 2016. 1. **[^](#cite_ref-5)** John Margaglione (November 30, 2010). ["What's new in Oracle Linux Part 1: OCFS2 1.6 REFLINKs"](https://web.archive.org/web/20170510113950/https://blogs.oracle.com/devpartner/entry/whats_new_in_oracle_linux). Oracle. Archived from [the original](https://blogs.oracle.com/devpartner/entry/whats_new_in_oracle_linux) on May 10, 2017. Retrieved May 10, 2017. ## External links - [OCFS2](http://oss.oracle.com/projects/ocfs2/) project page - [OCFS](http://oss.oracle.com/projects/ocfs/) project page - ["OCFS2 filesystem"](https://www.kernel.org/doc/Documentation/filesystems/ocfs2.txt). 2011-08-11. v t e File systems Comparison of file systems distributed Unix filesystem Disk and non-rotating ADFS AdvFS Amiga FFS Amiga OFS APFS AthFS bcachefs BFS Be File System Boot File System Byte File System (z/VM) Btrfs CVFS CXFS DFS EFS Encrypting File System Extent File System Episode ext ext2 ext3 ext4 FAT exFAT Files-11 Fossil GPFS HAMMER HAMMER2 HFS (Classic Mac OS) HFS (MVS) HFS+ HPFS HTFS JFS LFS MFS Macintosh File System TiVo Media File System MINIX NetWare File System Next3 NILFS NILFS2 NSS NTFS OneFS OpenZFS PFS QFS QNX4FS ReFS ReiserFS Reiser4 Reliance Reliance Nitro RFS SFS Shared File System (VM) Smart File System SNFS Soup (Apple) Tux3 UBIFS UFS/UFS2 soft updates WAPBL VxFS WAFL Xiafs XFS Xsan zFS (z/OS) ZFS (Sun) Optical disc HSF ISO 9660 ISO 13490 UDF Flash memory and SSD APFS FAT exFAT TFAT EROFS F2FS JFS NVFS host-side wear leveling CHFS JFFS JFFS2 LogFS NILFS NILFS2 YAFFS UBIFS Distributed parallel BeeGFS Ceph CXFS GFS2 Google File System OCFS2 OrangeFS PVFS QFS Xsan more... NAS 9P AFS (OpenAFS) AFP Coda DFS Google File System GPFS Lustre NCP NFS POHMELFS Hadoop SMB (CIFS) SSHFS more... Specialized Aufs AXFS Boot File System Compact Disc File System cramfs Davfs2 EROFS FTPFS FUSE Lnfs LTFS NOVA MVFS SquashFS UMSDOS OverlayFS UnionFS Pseudo configfs devfs debugfs kernfs procfs specfs sysfs tmpfs WinFS Encrypted eCryptfs EncFS EFS Rubberhose SSHFS ZFS Types Clustered Global Grid Self-certifying Flash Journaling Log-structured Object Record-oriented Semantic Steganographic Synthetic Versioning Features Case preservation Copy-on-write Data deduplication Data scrubbing Execute in place Extent File attribute Extended file attributes File change log Fork Inode Links Hard Symbolic Access control Access-control list Filesystem-level encryption Permissions Modes Sticky bit Interfaces File manager File system API Installable File System Virtual file system Lists Cryptographic Default Log-structured Layouts Master Boot Record GUID Partition Table Apple Partition Map v t e Oracle Corporation Corporate directors Jeffrey Berg H. 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Oracle America, Inc. Italics = discontinued • Category --- Adapted from the Wikipedia article [OCFS2](https://en.wikipedia.org/wiki/OCFS2) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/OCFS2?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.