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+OCFS2 filesystem
+OCFS2 is a general purpose extent based shared disk cluster file
+system with many similarities to ext3. It supports 64 bit inode
+numbers, and has automatically extending metadata groups which may
+also make it attractive for non-clustered use.
+You'll want to install the ocfs2-tools package in order to at least
+get "mount.ocfs2" and "ocfs2_hb_ctl".
+Project web page: http://oss.oracle.com/projects/ocfs2
+Tools web page: http://oss.oracle.com/projects/ocfs2-tools
+OCFS2 mailing lists: http://oss.oracle.com/projects/ocfs2/mailman/
+All code copyright 2005 Oracle except when otherwise noted.
+Lots of code taken from ext3 and other projects.
+Authors in alphabetical order:
+Joel Becker <joel.becker@oracle.com>
+Zach Brown <zach.brown@oracle.com>
+Mark Fasheh <mfasheh@suse.com>
+Kurt Hackel <kurt.hackel@oracle.com>
+Tao Ma <tao.ma@oracle.com>
+Sunil Mushran <sunil.mushran@oracle.com>
+Manish Singh <manish.singh@oracle.com>
+Tiger Yang <tiger.yang@oracle.com>
+Features which OCFS2 does not support yet:
+ - Directory change notification (F_NOTIFY)
+ - Distributed Caching (F_SETLEASE/F_GETLEASE/break_lease)
+Mount options
+OCFS2 supports the following mount options:
+(*) == default
+barrier=1 This enables/disables barriers. barrier=0 disables it,
+ barrier=1 enables it.
+errors=remount-ro(*) Remount the filesystem read-only on an error.
+errors=panic Panic and halt the machine if an error occurs.
+intr (*) Allow signals to interrupt cluster operations.
+nointr Do not allow signals to interrupt cluster
+ operations.
+noatime Do not update access time.
+relatime(*) Update atime if the previous atime is older than
+ mtime or ctime
+strictatime Always update atime, but the minimum update interval
+ is specified by atime_quantum.
+atime_quantum=60(*) OCFS2 will not update atime unless this number
+ of seconds has passed since the last update.
+ Set to zero to always update atime. This option need
+ work with strictatime.
+data=ordered (*) All data are forced directly out to the main file
+ system prior to its metadata being committed to the
+ journal.
+data=writeback Data ordering is not preserved, data may be written
+ into the main file system after its metadata has been
+ committed to the journal.
+preferred_slot=0(*) During mount, try to use this filesystem slot first. If
+ it is in use by another node, the first empty one found
+ will be chosen. Invalid values will be ignored.
+commit=nrsec (*) Ocfs2 can be told to sync all its data and metadata
+ every 'nrsec' seconds. The default value is 5 seconds.
+ This means that if you lose your power, you will lose
+ as much as the latest 5 seconds of work (your
+ filesystem will not be damaged though, thanks to the
+ journaling). This default value (or any low value)
+ will hurt performance, but it's good for data-safety.
+ Setting it to 0 will have the same effect as leaving
+ it at the default (5 seconds).
+ Setting it to very large values will improve
+ performance.
+localalloc=8(*) Allows custom localalloc size in MB. If the value is too
+ large, the fs will silently revert it to the default.
+localflocks This disables cluster aware flock.
+inode64 Indicates that Ocfs2 is allowed to create inodes at
+ any location in the filesystem, including those which
+ will result in inode numbers occupying more than 32
+ bits of significance.
+user_xattr (*) Enables Extended User Attributes.
+nouser_xattr Disables Extended User Attributes.
+acl Enables POSIX Access Control Lists support.
+noacl (*) Disables POSIX Access Control Lists support.
+resv_level=2 (*) Set how aggressive allocation reservations will be.
+ Valid values are between 0 (reservations off) to 8
+ (maximum space for reservations).
+dir_resv_level= (*) By default, directory reservations will scale with file
+ reservations - users should rarely need to change this
+ value. If allocation reservations are turned off, this
+ option will have no effect.
+coherency=full (*) Disallow concurrent O_DIRECT writes, cluster inode
+ lock will be taken to force other nodes drop cache,
+ therefore full cluster coherency is guaranteed even
+ for O_DIRECT writes.
+coherency=buffered Allow concurrent O_DIRECT writes without EX lock among
+ nodes, which gains high performance at risk of getting
+ stale data on other nodes.