projects / linux-2.6-block.git / blame
| Commit | Line | Data |
|---|---|---|
| e4731420 DT |
1 | Global File System |
| 2 | ------------------ | |
| 3 | ||
| 4 | http://sources.redhat.com/cluster/ | |
| 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 | ||
| 14 | GFS uses interchangable inter-node locking mechanisms. Different lock | |
| 15 | modules can plug into GFS and each file system selects the appropriate | |
| 16 | lock module at mount time. Lock modules include: | |
| 17 | ||
| 18 | lock_nolock -- allows gfs to be used as a local file system | |
| 19 | ||
| 20 | lock_dlm -- uses a distributed lock manager (dlm) for inter-node locking | |
| 21 | The dlm is found at linux/fs/dlm/ | |
| 22 | ||
| 23 | In addition to interfacing with an external locking manager, a gfs lock | |
| 24 | module is responsible for interacting with external cluster management | |
| 25 | systems. Lock_dlm depends on user space cluster management systems found | |
| 26 | at the URL above. | |
| 27 | ||
| 28 | To use gfs as a local file system, no external clustering systems are | |
| 29 | needed, simply: | |
| 30 | ||
| 2fcb4a12 | 31 | $ mkfs -t gfs2 -p lock_nolock -j 1 /dev/block_device |
| e4731420 DT |
32 | $ mount -t gfs2 /dev/block_device /dir |
| 33 | ||
| 34 | GFS2 is not on-disk compatible with previous versions of GFS. | |
| 35 | ||
| 36 | The following man pages can be found at the URL above: | |
| e4731420 DT |
37 | gfs2_fsck to repair a filesystem |
| 38 | gfs2_grow to expand a filesystem online | |
| 39 | gfs2_jadd to add journals to a filesystem online | |
| 40 | gfs2_tool to manipulate, examine and tune a filesystem | |
| 41 | gfs2_quota to examine and change quota values in a filesystem | |
| 373b5a45 DT |
42 | mount.gfs2 to help mount(8) mount a filesystem |
| 43 | mkfs.gfs2 to make a filesystem |