blob: 0b59c0200912853a3ccd6f6baa70646ada1c1766 [file] [log] [blame]
David Teiglande4731422006-01-18 09:21:38 +00001Global File System
2------------------
3
Andrea Gelmini4cb947b2010-03-25 11:04:49 +01004http://sources.redhat.com/cluster/wiki/
David Teiglande4731422006-01-18 09:21:38 +00005
6GFS is a cluster file system. It allows a cluster of computers to
7simultaneously use a block device that is shared between them (with FC,
8iSCSI, NBD, etc). GFS reads and writes to the block device like a local
9file system, but also uses a lock module to allow the computers coordinate
10their I/O so file system consistency is maintained. One of the nifty
11features of GFS is perfect consistency -- changes made to the file system
12on one machine show up immediately on all other machines in the cluster.
13
Steven Whitehousee9ccb732009-05-19 10:23:23 +010014GFS uses interchangable inter-node locking mechanisms, the currently
15supported mechanisms are:
David Teiglande4731422006-01-18 09:21:38 +000016
17 lock_nolock -- allows gfs to be used as a local file system
18
19 lock_dlm -- uses a distributed lock manager (dlm) for inter-node locking
20 The dlm is found at linux/fs/dlm/
21
Steven Whitehousee9ccb732009-05-19 10:23:23 +010022Lock_dlm depends on user space cluster management systems found
David Teiglande4731422006-01-18 09:21:38 +000023at the URL above.
24
25To use gfs as a local file system, no external clustering systems are
26needed, simply:
27
Steven Whitehouse2fcb4a12006-02-24 10:42:20 -050028 $ mkfs -t gfs2 -p lock_nolock -j 1 /dev/block_device
David Teiglande4731422006-01-18 09:21:38 +000029 $ mount -t gfs2 /dev/block_device /dir
30
Steven Whitehousee9ccb732009-05-19 10:23:23 +010031If you are using Fedora, you need to install the gfs2-utils package
32and, for lock_dlm, you will also need to install the cman package
33and write a cluster.conf as per the documentation.
34
35GFS2 is not on-disk compatible with previous versions of GFS, but it
36is pretty close.
David Teiglande4731422006-01-18 09:21:38 +000037
38The following man pages can be found at the URL above:
Andrea Gelmini4cb947b2010-03-25 11:04:49 +010039 fsck.gfs2 to repair a filesystem
40 gfs2_grow to expand a filesystem online
41 gfs2_jadd to add journals to a filesystem online
42 gfs2_tool to manipulate, examine and tune a filesystem
David Teiglande4731422006-01-18 09:21:38 +000043 gfs2_quota to examine and change quota values in a filesystem
Steven Whitehousee9ccb732009-05-19 10:23:23 +010044 gfs2_convert to convert a gfs filesystem to gfs2 in-place
David Teigland373b5a42006-04-25 15:44:04 -040045 mount.gfs2 to help mount(8) mount a filesystem
Andrea Gelmini4cb947b2010-03-25 11:04:49 +010046 mkfs.gfs2 to make a filesystem