1 .. SPDX-License-Identifier: GPL-2.0
2
3 ================
4 OCFS2 filesystem
5 ================
6
7 OCFS2 is a general purpose extent based shared
8 system with many similarities to ext3. It supp
9 numbers, and has automatically extending metad
10 also make it attractive for non-clustered use.
11
12 You'll want to install the ocfs2-tools package
13 get "mount.ocfs2" and "ocfs2_hb_ctl".
14
15 Project web page: http://ocfs2.wiki.kernel.
16 Tools git tree: https://github.com/markfa
17 OCFS2 mailing lists: https://subspace.kernel.o
18
19 All code copyright 2005 Oracle except when oth
20
21 Credits
22 =======
23
24 Lots of code taken from ext3 and other project
25
26 Authors in alphabetical order:
27
28 - Joel Becker <joel.becker@oracle.com>
29 - Zach Brown <zach.brown@oracle.com>
30 - Mark Fasheh <mfasheh@suse.com>
31 - Kurt Hackel <kurt.hackel@oracle.com>
32 - Tao Ma <tao.ma@oracle.com>
33 - Sunil Mushran <sunil.mushran@oracle.com>
34 - Manish Singh <manish.singh@oracle.com>
35 - Tiger Yang <tiger.yang@oracle.com>
36
37 Caveats
38 =======
39 Features which OCFS2 does not support yet:
40
41 - Directory change notification (F_NOT
42 - Distributed Caching (F_SETLEASE/F_GE
43
44 Mount options
45 =============
46
47 OCFS2 supports the following mount options:
48
49 (*) == default
50
51 ======================= ======================
52 barrier=1 This enables/disables
53 barrier=1 enables it.
54 errors=remount-ro(*) Remount the filesystem
55 errors=panic Panic and halt the mac
56 intr (*) Allow signals to inter
57 nointr Do not allow signals t
58 operations.
59 noatime Do not update access t
60 relatime(*) Update atime if the pr
61 mtime or ctime
62 strictatime Always update atime, b
63 is specified by atime_
64 atime_quantum=60(*) OCFS2 will not update
65 of seconds has passed
66 Set to zero to always
67 work with strictatime.
68 data=ordered (*) All data are forced di
69 system prior to its me
70 journal.
71 data=writeback Data ordering is not p
72 into the main file sys
73 committed to the journ
74 preferred_slot=0(*) During mount, try to u
75 it is in use by anothe
76 will be chosen. Invali
77 commit=nrsec (*) Ocfs2 can be told to s
78 every 'nrsec' seconds.
79 This means that if you
80 as much as the latest
81 filesystem will not be
82 journaling). This def
83 will hurt performance,
84 Setting it to 0 will h
85 it at the default (5 s
86 Setting it to very lar
87 performance.
88 localalloc=8(*) Allows custom localall
89 large, the fs will sil
90 localflocks This disables cluster
91 inode64 Indicates that Ocfs2 i
92 any location in the fi
93 will result in inode n
94 bits of significance.
95 user_xattr (*) Enables Extended User
96 nouser_xattr Disables Extended User
97 acl Enables POSIX Access C
98 noacl (*) Disables POSIX Access
99 resv_level=2 (*) Set how aggressive all
100 Valid values are betwe
101 (maximum space for res
102 dir_resv_level= (*) By default, directory
103 reservations - users s
104 value. If allocation r
105 option will have no ef
106 coherency=full (*) Disallow concurrent O_
107 lock will be taken to
108 therefore full cluster
109 for O_DIRECT writes.
110 coherency=buffered Allow concurrent O_DIR
111 nodes, which gains hig
112 stale data on other no
113 journal_async_commit Commit block can be wr
114 for descriptor blocks.
115 mount the device. This
116 internally.
117 ======================= ======================
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