1fa95e087SMauro Carvalho Chehab.. SPDX-License-Identifier: GPL-2.0 2fa95e087SMauro Carvalho Chehab 3fa95e087SMauro Carvalho Chehab================ 4fa95e087SMauro Carvalho ChehabOCFS2 filesystem 5fa95e087SMauro Carvalho Chehab================ 6fa95e087SMauro Carvalho Chehab 7fa95e087SMauro Carvalho ChehabOCFS2 is a general purpose extent based shared disk cluster file 8fa95e087SMauro Carvalho Chehabsystem with many similarities to ext3. It supports 64 bit inode 9fa95e087SMauro Carvalho Chehabnumbers, and has automatically extending metadata groups which may 10fa95e087SMauro Carvalho Chehabalso make it attractive for non-clustered use. 11fa95e087SMauro Carvalho Chehab 12fa95e087SMauro Carvalho ChehabYou'll want to install the ocfs2-tools package in order to at least 13fa95e087SMauro Carvalho Chehabget "mount.ocfs2" and "ocfs2_hb_ctl". 14fa95e087SMauro Carvalho Chehab 15fa95e087SMauro Carvalho ChehabProject web page: http://ocfs2.wiki.kernel.org 16fa95e087SMauro Carvalho ChehabTools git tree: https://github.com/markfasheh/ocfs2-tools 17*5a569db6SAnthony IliopoulosOCFS2 mailing lists: https://subspace.kernel.org/lists.linux.dev.html 18fa95e087SMauro Carvalho Chehab 19fa95e087SMauro Carvalho ChehabAll code copyright 2005 Oracle except when otherwise noted. 20fa95e087SMauro Carvalho Chehab 21fa95e087SMauro Carvalho ChehabCredits 22fa95e087SMauro Carvalho Chehab======= 23fa95e087SMauro Carvalho Chehab 24fa95e087SMauro Carvalho ChehabLots of code taken from ext3 and other projects. 25fa95e087SMauro Carvalho Chehab 26fa95e087SMauro Carvalho ChehabAuthors in alphabetical order: 27fa95e087SMauro Carvalho Chehab 28fa95e087SMauro Carvalho Chehab- Joel Becker <joel.becker@oracle.com> 29fa95e087SMauro Carvalho Chehab- Zach Brown <zach.brown@oracle.com> 30fa95e087SMauro Carvalho Chehab- Mark Fasheh <mfasheh@suse.com> 31fa95e087SMauro Carvalho Chehab- Kurt Hackel <kurt.hackel@oracle.com> 32fa95e087SMauro Carvalho Chehab- Tao Ma <tao.ma@oracle.com> 33fa95e087SMauro Carvalho Chehab- Sunil Mushran <sunil.mushran@oracle.com> 34fa95e087SMauro Carvalho Chehab- Manish Singh <manish.singh@oracle.com> 35fa95e087SMauro Carvalho Chehab- Tiger Yang <tiger.yang@oracle.com> 36fa95e087SMauro Carvalho Chehab 37fa95e087SMauro Carvalho ChehabCaveats 38fa95e087SMauro Carvalho Chehab======= 39fa95e087SMauro Carvalho ChehabFeatures which OCFS2 does not support yet: 40fa95e087SMauro Carvalho Chehab 41fa95e087SMauro Carvalho Chehab - Directory change notification (F_NOTIFY) 42fa95e087SMauro Carvalho Chehab - Distributed Caching (F_SETLEASE/F_GETLEASE/break_lease) 43fa95e087SMauro Carvalho Chehab 44fa95e087SMauro Carvalho ChehabMount options 45fa95e087SMauro Carvalho Chehab============= 46fa95e087SMauro Carvalho Chehab 47fa95e087SMauro Carvalho ChehabOCFS2 supports the following mount options: 48fa95e087SMauro Carvalho Chehab 49fa95e087SMauro Carvalho Chehab(*) == default 50fa95e087SMauro Carvalho Chehab 51fa95e087SMauro Carvalho Chehab======================= ======================================================== 52fa95e087SMauro Carvalho Chehabbarrier=1 This enables/disables barriers. barrier=0 disables it, 53fa95e087SMauro Carvalho Chehab barrier=1 enables it. 54fa95e087SMauro Carvalho Chehaberrors=remount-ro(*) Remount the filesystem read-only on an error. 55fa95e087SMauro Carvalho Chehaberrors=panic Panic and halt the machine if an error occurs. 56fa95e087SMauro Carvalho Chehabintr (*) Allow signals to interrupt cluster operations. 57fa95e087SMauro Carvalho Chehabnointr Do not allow signals to interrupt cluster 58fa95e087SMauro Carvalho Chehab operations. 59fa95e087SMauro Carvalho Chehabnoatime Do not update access time. 60fa95e087SMauro Carvalho Chehabrelatime(*) Update atime if the previous atime is older than 61fa95e087SMauro Carvalho Chehab mtime or ctime 62fa95e087SMauro Carvalho Chehabstrictatime Always update atime, but the minimum update interval 63fa95e087SMauro Carvalho Chehab is specified by atime_quantum. 64fa95e087SMauro Carvalho Chehabatime_quantum=60(*) OCFS2 will not update atime unless this number 65fa95e087SMauro Carvalho Chehab of seconds has passed since the last update. 66fa95e087SMauro Carvalho Chehab Set to zero to always update atime. This option need 67fa95e087SMauro Carvalho Chehab work with strictatime. 68fa95e087SMauro Carvalho Chehabdata=ordered (*) All data are forced directly out to the main file 69fa95e087SMauro Carvalho Chehab system prior to its metadata being committed to the 70fa95e087SMauro Carvalho Chehab journal. 71fa95e087SMauro Carvalho Chehabdata=writeback Data ordering is not preserved, data may be written 72fa95e087SMauro Carvalho Chehab into the main file system after its metadata has been 73fa95e087SMauro Carvalho Chehab committed to the journal. 74fa95e087SMauro Carvalho Chehabpreferred_slot=0(*) During mount, try to use this filesystem slot first. If 75fa95e087SMauro Carvalho Chehab it is in use by another node, the first empty one found 76fa95e087SMauro Carvalho Chehab will be chosen. Invalid values will be ignored. 77fa95e087SMauro Carvalho Chehabcommit=nrsec (*) Ocfs2 can be told to sync all its data and metadata 78fa95e087SMauro Carvalho Chehab every 'nrsec' seconds. The default value is 5 seconds. 79fa95e087SMauro Carvalho Chehab This means that if you lose your power, you will lose 80fa95e087SMauro Carvalho Chehab as much as the latest 5 seconds of work (your 81fa95e087SMauro Carvalho Chehab filesystem will not be damaged though, thanks to the 82fa95e087SMauro Carvalho Chehab journaling). This default value (or any low value) 83fa95e087SMauro Carvalho Chehab will hurt performance, but it's good for data-safety. 84fa95e087SMauro Carvalho Chehab Setting it to 0 will have the same effect as leaving 85fa95e087SMauro Carvalho Chehab it at the default (5 seconds). 86fa95e087SMauro Carvalho Chehab Setting it to very large values will improve 87fa95e087SMauro Carvalho Chehab performance. 88fa95e087SMauro Carvalho Chehablocalalloc=8(*) Allows custom localalloc size in MB. If the value is too 89fa95e087SMauro Carvalho Chehab large, the fs will silently revert it to the default. 90fa95e087SMauro Carvalho Chehablocalflocks This disables cluster aware flock. 91fa95e087SMauro Carvalho Chehabinode64 Indicates that Ocfs2 is allowed to create inodes at 92fa95e087SMauro Carvalho Chehab any location in the filesystem, including those which 93fa95e087SMauro Carvalho Chehab will result in inode numbers occupying more than 32 94fa95e087SMauro Carvalho Chehab bits of significance. 95fa95e087SMauro Carvalho Chehabuser_xattr (*) Enables Extended User Attributes. 96fa95e087SMauro Carvalho Chehabnouser_xattr Disables Extended User Attributes. 97fa95e087SMauro Carvalho Chehabacl Enables POSIX Access Control Lists support. 98fa95e087SMauro Carvalho Chehabnoacl (*) Disables POSIX Access Control Lists support. 99fa95e087SMauro Carvalho Chehabresv_level=2 (*) Set how aggressive allocation reservations will be. 100fa95e087SMauro Carvalho Chehab Valid values are between 0 (reservations off) to 8 101fa95e087SMauro Carvalho Chehab (maximum space for reservations). 102fa95e087SMauro Carvalho Chehabdir_resv_level= (*) By default, directory reservations will scale with file 103fa95e087SMauro Carvalho Chehab reservations - users should rarely need to change this 104fa95e087SMauro Carvalho Chehab value. If allocation reservations are turned off, this 105fa95e087SMauro Carvalho Chehab option will have no effect. 106fa95e087SMauro Carvalho Chehabcoherency=full (*) Disallow concurrent O_DIRECT writes, cluster inode 107fa95e087SMauro Carvalho Chehab lock will be taken to force other nodes drop cache, 108fa95e087SMauro Carvalho Chehab therefore full cluster coherency is guaranteed even 109fa95e087SMauro Carvalho Chehab for O_DIRECT writes. 110fa95e087SMauro Carvalho Chehabcoherency=buffered Allow concurrent O_DIRECT writes without EX lock among 111fa95e087SMauro Carvalho Chehab nodes, which gains high performance at risk of getting 112fa95e087SMauro Carvalho Chehab stale data on other nodes. 113fa95e087SMauro Carvalho Chehabjournal_async_commit Commit block can be written to disk without waiting 114fa95e087SMauro Carvalho Chehab for descriptor blocks. If enabled older kernels cannot 115fa95e087SMauro Carvalho Chehab mount the device. This will enable 'journal_checksum' 116fa95e087SMauro Carvalho Chehab internally. 117fa95e087SMauro Carvalho Chehab======================= ======================================================== 118