| David Teigland | e473142 | 2006-01-18 09:21:38 +0000 | [diff] [blame] | 1 | Global File System |
| 2 | ------------------ |
| 3 | |
| Andrea Gelmini | 4cb947b | 2010-03-25 11:04:49 +0100 | [diff] [blame] | 4 | http://sources.redhat.com/cluster/wiki/ |
| David Teigland | e473142 | 2006-01-18 09:21:38 +0000 | [diff] [blame] | 5 | |
| 6 | GFS is a cluster file system. It allows a cluster of computers to |
| 7 | simultaneously use a block device that is shared between them (with FC, |
| 8 | iSCSI, NBD, etc). GFS reads and writes to the block device like a local |
| 9 | file system, but also uses a lock module to allow the computers coordinate |
| 10 | their I/O so file system consistency is maintained. One of the nifty |
| 11 | features of GFS is perfect consistency -- changes made to the file system |
| 12 | on one machine show up immediately on all other machines in the cluster. |
| 13 | |
| Lucas De Marchi | 25985ed | 2011-03-30 22:57:33 -0300 | [diff] [blame] | 14 | GFS uses interchangeable inter-node locking mechanisms, the currently |
| Steven Whitehouse | e9ccb73 | 2009-05-19 10:23:23 +0100 | [diff] [blame] | 15 | supported mechanisms are: |
| David Teigland | e473142 | 2006-01-18 09:21:38 +0000 | [diff] [blame] | 16 | |
| 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 Whitehouse | e9ccb73 | 2009-05-19 10:23:23 +0100 | [diff] [blame] | 22 | Lock_dlm depends on user space cluster management systems found |
| David Teigland | e473142 | 2006-01-18 09:21:38 +0000 | [diff] [blame] | 23 | at the URL above. |
| 24 | |
| 25 | To use gfs as a local file system, no external clustering systems are |
| 26 | needed, simply: |
| 27 | |
| Steven Whitehouse | 2fcb4a1 | 2006-02-24 10:42:20 -0500 | [diff] [blame] | 28 | $ mkfs -t gfs2 -p lock_nolock -j 1 /dev/block_device |
| David Teigland | e473142 | 2006-01-18 09:21:38 +0000 | [diff] [blame] | 29 | $ mount -t gfs2 /dev/block_device /dir |
| 30 | |
| Steven Whitehouse | e9ccb73 | 2009-05-19 10:23:23 +0100 | [diff] [blame] | 31 | If you are using Fedora, you need to install the gfs2-utils package |
| 32 | and, for lock_dlm, you will also need to install the cman package |
| 33 | and write a cluster.conf as per the documentation. |
| 34 | |
| 35 | GFS2 is not on-disk compatible with previous versions of GFS, but it |
| 36 | is pretty close. |
| David Teigland | e473142 | 2006-01-18 09:21:38 +0000 | [diff] [blame] | 37 | |
| 38 | The following man pages can be found at the URL above: |
| Andrea Gelmini | 4cb947b | 2010-03-25 11:04:49 +0100 | [diff] [blame] | 39 | 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 Teigland | e473142 | 2006-01-18 09:21:38 +0000 | [diff] [blame] | 43 | gfs2_quota to examine and change quota values in a filesystem |
| Steven Whitehouse | e9ccb73 | 2009-05-19 10:23:23 +0100 | [diff] [blame] | 44 | gfs2_convert to convert a gfs filesystem to gfs2 in-place |
| David Teigland | 373b5a4 | 2006-04-25 15:44:04 -0400 | [diff] [blame] | 45 | mount.gfs2 to help mount(8) mount a filesystem |
| Andrea Gelmini | 4cb947b | 2010-03-25 11:04:49 +0100 | [diff] [blame] | 46 | mkfs.gfs2 to make a filesystem |