projects / linux-block.git / blame
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|---|---|---|
| 720c2fc1 MCC |
1 | .. SPDX-License-Identifier: GPL-2.0 |
| 2 | ||
| d9593868 AP |
3 | ==================== |
| 4 | Global File System 2 | |
| 5 | ==================== | |
| e4731420 | 6 | |
| d9593868 | 7 | GFS2 is a cluster file system. It allows a cluster of computers to |
| e4731420 | 8 | simultaneously use a block device that is shared between them (with FC, |
| d9593868 | 9 | iSCSI, NBD, etc). GFS2 reads and writes to the block device like a local |
| e4731420 DT |
10 | file system, but also uses a lock module to allow the computers coordinate |
| 11 | their I/O so file system consistency is maintained. One of the nifty | |
| d9593868 | 12 | features of GFS2 is perfect consistency -- changes made to the file system |
| e4731420 DT |
13 | on one machine show up immediately on all other machines in the cluster. |
| 14 | ||
| d9593868 | 15 | GFS2 uses interchangeable inter-node locking mechanisms, the currently |
| e9ccb73a | 16 | supported mechanisms are: |
| e4731420 | 17 | |
| 720c2fc1 | 18 | lock_nolock |
| d9593868 | 19 | - allows GFS2 to be used as a local file system |
| e4731420 | 20 | |
| 720c2fc1 | 21 | lock_dlm |
| d9593868 | 22 | - uses the distributed lock manager (dlm) for inter-node locking. |
| 720c2fc1 | 23 | The dlm is found at linux/fs/dlm/ |
| e4731420 | 24 | |
| d9593868 | 25 | lock_dlm depends on user space cluster management systems found |
| e4731420 DT |
26 | at the URL above. |
| 27 | ||
| d9593868 | 28 | To use GFS2 as a local file system, no external clustering systems are |
| 720c2fc1 | 29 | needed, simply:: |
| e4731420 | 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 | ||
| d9593868 AP |
34 | The gfs2-utils package is required on all cluster nodes and, for lock_dlm, you |
| 35 | will also need the dlm and corosync user space utilities configured as per the | |
| 36 | documentation. | |
| 37 | ||
| 38 | gfs2-utils can be found at https://pagure.io/gfs2-utils | |
| e9ccb73a SW |
39 | |
| 40 | GFS2 is not on-disk compatible with previous versions of GFS, but it | |
| 41 | is pretty close. | |
| e4731420 | 42 | |
| d9593868 | 43 | The following man pages are available from gfs2-utils: |
| 720c2fc1 MCC |
44 | |
| 45 | ============ ============================================= | |
| 4cb947b5 AG |
46 | fsck.gfs2 to repair a filesystem |
| 47 | gfs2_grow to expand a filesystem online | |
| 48 | gfs2_jadd to add journals to a filesystem online | |
| 49f30789 | 49 | tunegfs2 to manipulate, examine and tune a filesystem |
| d9593868 | 50 | gfs2_convert to convert a gfs filesystem to GFS2 in-place |
| 4cb947b5 | 51 | mkfs.gfs2 to make a filesystem |
| 720c2fc1 | 52 | ============ ============================================= |