OCFS

OCFS
OCFS2
Developer Oracle Corporation
Full name Oracle Cluster File System
Introduced March 2006 (Linux 2.6.16)
Limits
Max file size 4 PB (OCFS2)[1]
Max filename length 255 bytes
Max volume size 4 PB (OCFS2)[1]
Allowed characters in filenames 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
Supported operating systems Linux

OCFS (Oracle Cluster File System) 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 database files for clustered databases. 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 more features have been included into ocfs2 especially access control lists and quota.[2]

OCFS2 uses a distributed lock manager which resembles the OpenVMS DLM but is much simpler.[3]

See also

Notes and references

  1. ^ a b Currently limited to 16TiB since it uses the Linux JBD
  2. ^ http://thread.gmane.org/gmane.linux.kernel/775637
  3. ^ http://lwn.net/Articles/137278/

External links

  • OCFS2 project page
  • OCFS project page
  • [1] in the Linux tree