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Mark Fashehccd979b2005-12-15 14:31:24 -08001OCFS2 filesystem
2==================
3OCFS2 is a general purpose extent based shared disk cluster file
4system with many similarities to ext3. It supports 64 bit inode
5numbers, and has automatically extending metadata groups which may
6also make it attractive for non-clustered use.
7
8You'll want to install the ocfs2-tools package in order to at least
9get "mount.ocfs2" and "ocfs2_hb_ctl".
10
11Project web page: http://oss.oracle.com/projects/ocfs2
12Tools web page: http://oss.oracle.com/projects/ocfs2-tools
13OCFS2 mailing lists: http://oss.oracle.com/projects/ocfs2/mailman/
14
15All code copyright 2005 Oracle except when otherwise noted.
16
17CREDITS:
18Lots of code taken from ext3 and other projects.
19
20Authors in alphabetical order:
21Joel Becker <joel.becker@oracle.com>
22Zach Brown <zach.brown@oracle.com>
Sunil Mushran7ab8f522009-11-02 13:38:10 -080023Mark Fasheh <mfasheh@suse.com>
Mark Fashehccd979b2005-12-15 14:31:24 -080024Kurt Hackel <kurt.hackel@oracle.com>
Sunil Mushran7ab8f522009-11-02 13:38:10 -080025Tao Ma <tao.ma@oracle.com>
Mark Fashehccd979b2005-12-15 14:31:24 -080026Sunil Mushran <sunil.mushran@oracle.com>
27Manish Singh <manish.singh@oracle.com>
Sunil Mushran7ab8f522009-11-02 13:38:10 -080028Tiger Yang <tiger.yang@oracle.com>
Mark Fashehccd979b2005-12-15 14:31:24 -080029
30Caveats
31=======
32Features which OCFS2 does not support yet:
Mark Fashehccd979b2005-12-15 14:31:24 -080033 - Directory change notification (F_NOTIFY)
34 - Distributed Caching (F_SETLEASE/F_GETLEASE/break_lease)
Mark Fashehccd979b2005-12-15 14:31:24 -080035
36Mount options
37=============
38
39OCFS2 supports the following mount options:
40(*) == default
41
42barrier=1 This enables/disables barriers. barrier=0 disables it,
43 barrier=1 enables it.
44errors=remount-ro(*) Remount the filesystem read-only on an error.
45errors=panic Panic and halt the machine if an error occurs.
46intr (*) Allow signals to interrupt cluster operations.
47nointr Do not allow signals to interrupt cluster
48 operations.
Tiger Yangbcd56252006-12-05 10:09:17 +080049atime_quantum=60(*) OCFS2 will not update atime unless this number
50 of seconds has passed since the last update.
51 Set to zero to always update atime.
Mark Fasheh10b08452007-08-23 11:17:55 -070052data=ordered (*) All data are forced directly out to the main file
53 system prior to its metadata being committed to the
54 journal.
55data=writeback Data ordering is not preserved, data may be written
56 into the main file system after its metadata has been
57 committed to the journal.
58preferred_slot=0(*) During mount, try to use this filesystem slot first. If
59 it is in use by another node, the first empty one found
60 will be chosen. Invalid values will be ignored.
Mark Fashehd147b3d2007-11-07 14:40:36 -080061commit=nrsec (*) Ocfs2 can be told to sync all its data and metadata
62 every 'nrsec' seconds. The default value is 5 seconds.
63 This means that if you lose your power, you will lose
64 as much as the latest 5 seconds of work (your
65 filesystem will not be damaged though, thanks to the
66 journaling). This default value (or any low value)
67 will hurt performance, but it's good for data-safety.
68 Setting it to 0 will have the same effect as leaving
69 it at the default (5 seconds).
70 Setting it to very large values will improve
71 performance.
Sunil Mushran2fbe8d12007-12-20 14:58:11 -080072localalloc=8(*) Allows custom localalloc size in MB. If the value is too
73 large, the fs will silently revert it to the default.
Mark Fasheh53fc6222007-12-20 16:49:04 -080074localflocks This disables cluster aware flock.
Joel Becker12462f12008-09-03 20:03:40 -070075inode64 Indicates that Ocfs2 is allowed to create inodes at
76 any location in the filesystem, including those which
77 will result in inode numbers occupying more than 32
78 bits of significance.
Mark Fasheh696b55d2008-10-07 11:09:24 -070079user_xattr (*) Enables Extended User Attributes.
80nouser_xattr Disables Extended User Attributes.
Tiger Yanga68979b2008-11-14 11:17:52 +080081acl Enables POSIX Access Control Lists support.
82noacl (*) Disables POSIX Access Control Lists support.