Based on kernel version 2.6.26. Page generated on 2008-07-16 21:12 EST.
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[AT]oracle[DOT]com> 22 Zach Brown <zach.brown[AT]oracle[DOT]com> 23 Mark Fasheh <mark.fasheh[AT]oracle[DOT]com> 24 Kurt Hackel <kurt.hackel[AT]oracle[DOT]com> 25 Sunil Mushran <sunil.mushran[AT]oracle[DOT]com> 26 Manish Singh <manish.singh[AT]oracle[DOT]com> 27 28 Caveats 29 ======= 30 Features which OCFS2 does not support yet: 31 - extended attributes 32 - quotas 33 - cluster aware flock 34 - cluster aware lockf 35 - Directory change notification (F_NOTIFY) 36 - Distributed Caching (F_SETLEASE/F_GETLEASE/break_lease) 37 - POSIX ACLs 38 39 Mount options 40 ============= 41 42 OCFS2 supports the following mount options: 43 (*) == default 44 45 barrier=1 This enables/disables barriers. barrier=0 disables it, 46 barrier=1 enables it. 47 errors=remount-ro(*) Remount the filesystem read-only on an error. 48 errors=panic Panic and halt the machine if an error occurs. 49 intr (*) Allow signals to interrupt cluster operations. 50 nointr Do not allow signals to interrupt cluster 51 operations. 52 atime_quantum=60(*) OCFS2 will not update atime unless this number 53 of seconds has passed since the last update. 54 Set to zero to always update atime. 55 data=ordered (*) All data are forced directly out to the main file 56 system prior to its metadata being committed to the 57 journal. 58 data=writeback Data ordering is not preserved, data may be written 59 into the main file system after its metadata has been 60 committed to the journal. 61 preferred_slot=0(*) During mount, try to use this filesystem slot first. If 62 it is in use by another node, the first empty one found 63 will be chosen. Invalid values will be ignored. 64 commit=nrsec (*) Ocfs2 can be told to sync all its data and metadata 65 every 'nrsec' seconds. The default value is 5 seconds. 66 This means that if you lose your power, you will lose 67 as much as the latest 5 seconds of work (your 68 filesystem will not be damaged though, thanks to the 69 journaling). This default value (or any low value) 70 will hurt performance, but it's good for data-safety. 71 Setting it to 0 will have the same effect as leaving 72 it at the default (5 seconds). 73 Setting it to very large values will improve 74 performance. 75 localalloc=8(*) Allows custom localalloc size in MB. If the value is too 76 large, the fs will silently revert it to the default. 77 Localalloc is not enabled for local mounts. 78 localflocks This disables cluster aware flock.