git://bbs.cooldavid.org / net-next-2.6.git / blame
| Commit | Line | Data |
|---|---|---|
| ccd979bd MF |
1 | OCFS2 filesystem |
| 2 | ================== | |
| 3 | OCFS2 is a general purpose extent based shared disk cluster file | |
| 4 | system with many similarities to ext3. It supports 64 bit inode | |
| 5 | numbers, and has automatically extending metadata groups which may | |
| 6 | also make it attractive for non-clustered use. | |
| 7 | ||
| 8 | You'll want to install the ocfs2-tools package in order to at least | |
| 9 | get "mount.ocfs2" and "ocfs2_hb_ctl". | |
| 10 | ||
| 11 | Project web page: http://oss.oracle.com/projects/ocfs2 | |
| 12 | Tools web page: http://oss.oracle.com/projects/ocfs2-tools | |
| 13 | OCFS2 mailing lists: http://oss.oracle.com/projects/ocfs2/mailman/ | |
| 14 | ||
| 15 | All code copyright 2005 Oracle except when otherwise noted. | |
| 16 | ||
| 17 | CREDITS: | |
| 18 | Lots of code taken from ext3 and other projects. | |
| 19 | ||
| 20 | Authors in alphabetical order: | |
| 21 | Joel Becker <joel.becker@oracle.com> | |
| 22 | Zach Brown <zach.brown@oracle.com> | |
| 7ab8f524 | 23 | Mark Fasheh <mfasheh@suse.com> |
| ccd979bd | 24 | Kurt Hackel <kurt.hackel@oracle.com> |
| 7ab8f524 | 25 | Tao Ma <tao.ma@oracle.com> |
| ccd979bd MF |
26 | Sunil Mushran <sunil.mushran@oracle.com> |
| 27 | Manish Singh <manish.singh@oracle.com> | |
| 7ab8f524 | 28 | Tiger Yang <tiger.yang@oracle.com> |
| ccd979bd MF |
29 | |
| 30 | Caveats | |
| 31 | ======= | |
| 32 | Features which OCFS2 does not support yet: | |
| ccd979bd MF |
33 | - Directory change notification (F_NOTIFY) |
| 34 | - Distributed Caching (F_SETLEASE/F_GETLEASE/break_lease) | |
| ccd979bd MF |
35 | |
| 36 | Mount options | |
| 37 | ============= | |
| 38 | ||
| 39 | OCFS2 supports the following mount options: | |
| 40 | (*) == default | |
| 41 | ||
| 42 | barrier=1 This enables/disables barriers. barrier=0 disables it, | |
| 43 | barrier=1 enables it. | |
| 44 | errors=remount-ro(*) Remount the filesystem read-only on an error. | |
| 45 | errors=panic Panic and halt the machine if an error occurs. | |
| 46 | intr (*) Allow signals to interrupt cluster operations. | |
| 47 | nointr Do not allow signals to interrupt cluster | |
| 48 | operations. | |
| bcd5625b TY |
49 | atime_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. | |
| 10b0845b MF |
52 | data=ordered (*) All data are forced directly out to the main file |
| 53 | system prior to its metadata being committed to the | |
| 54 | journal. | |
| 55 | data=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. | |
| 58 | preferred_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. | |
| d147b3d6 MF |
61 | commit=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. | |
| 2fbe8d1e SM |
72 | localalloc=8(*) Allows custom localalloc size in MB. If the value is too |
| 73 | large, the fs will silently revert it to the default. | |
| 53fc622b | 74 | localflocks This disables cluster aware flock. |
| 12462f1d JB |
75 | inode64 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. | |
| 696b55d7 MF |
79 | user_xattr (*) Enables Extended User Attributes. |
| 80 | nouser_xattr Disables Extended User Attributes. | |
| a68979b8 TY |
81 | acl Enables POSIX Access Control Lists support. |
| 82 | noacl (*) Disables POSIX Access Control Lists support. | |
| b07f8f24 | 83 | resv_level=2 (*) Set how agressive allocation reservations will be. |
| d02f00cc MF |
84 | Valid values are between 0 (reservations off) to 8 |
| 85 | (maximum space for reservations). | |
| 83f92318 MF |
86 | dir_resv_level= (*) By default, directory reservations will scale with file |
| 87 | reservations - users should rarely need to change this | |
| 88 | value. If allocation reservations are turned off, this | |
| 89 | option will have no effect. | |
| 7bdb0d18 TY |
90 | coherency=full (*) Disallow concurrent O_DIRECT writes, cluster inode |
| 91 | lock will be taken to force other nodes drop cache, | |
| 92 | therefore full cluster coherency is guaranteed even | |
| 93 | for O_DIRECT writes. | |
| 94 | coherency=buffered Allow concurrent O_DIRECT writes without EX lock among | |
| 95 | nodes, which gains high performance at risk of getting | |
| 96 | stale data on other nodes. |