projects / thirdparty / linux.git / blame
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| 720c2fc1 MCC |
1 | .. SPDX-License-Identifier: GPL-2.0 |
| 2 | ||
| 3 | ================== | |
| e4731420 | 4 | Global File System |
| 720c2fc1 | 5 | ================== |
| e4731420 | 6 | |
| 49f30789 | 7 | https://fedorahosted.org/cluster/wiki/HomePage |
| e4731420 DT |
8 | |
| 9 | GFS is a cluster file system. It allows a cluster of computers to | |
| 10 | simultaneously use a block device that is shared between them (with FC, | |
| 11 | iSCSI, NBD, etc). GFS reads and writes to the block device like a local | |
| 12 | file system, but also uses a lock module to allow the computers coordinate | |
| 13 | their I/O so file system consistency is maintained. One of the nifty | |
| 14 | features of GFS is perfect consistency -- changes made to the file system | |
| 15 | on one machine show up immediately on all other machines in the cluster. | |
| 16 | ||
| 25985edc | 17 | GFS uses interchangeable inter-node locking mechanisms, the currently |
| e9ccb73a | 18 | supported mechanisms are: |
| e4731420 | 19 | |
| 720c2fc1 MCC |
20 | lock_nolock |
| 21 | - allows gfs to be used as a local file system | |
| e4731420 | 22 | |
| 720c2fc1 MCC |
23 | lock_dlm |
| 24 | - uses a distributed lock manager (dlm) for inter-node locking. | |
| 25 | The dlm is found at linux/fs/dlm/ | |
| e4731420 | 26 | |
| e9ccb73a | 27 | Lock_dlm depends on user space cluster management systems found |
| e4731420 DT |
28 | at the URL above. |
| 29 | ||
| 30 | To use gfs as a local file system, no external clustering systems are | |
| 720c2fc1 | 31 | needed, simply:: |
| e4731420 | 32 | |
| 2fcb4a12 | 33 | $ mkfs -t gfs2 -p lock_nolock -j 1 /dev/block_device |
| e4731420 DT |
34 | $ mount -t gfs2 /dev/block_device /dir |
| 35 | ||
| e9ccb73a SW |
36 | If you are using Fedora, you need to install the gfs2-utils package |
| 37 | and, for lock_dlm, you will also need to install the cman package | |
| 49f30789 SW |
38 | and write a cluster.conf as per the documentation. For F17 and above |
| 39 | cman has been replaced by the dlm package. | |
| e9ccb73a SW |
40 | |
| 41 | GFS2 is not on-disk compatible with previous versions of GFS, but it | |
| 42 | is pretty close. | |
| e4731420 DT |
43 | |
| 44 | The following man pages can be found at the URL above: | |
| 720c2fc1 MCC |
45 | |
| 46 | ============ ============================================= | |
| 4cb947b5 AG |
47 | fsck.gfs2 to repair a filesystem |
| 48 | gfs2_grow to expand a filesystem online | |
| 49 | gfs2_jadd to add journals to a filesystem online | |
| 49f30789 | 50 | tunegfs2 to manipulate, examine and tune a filesystem |
| 720c2fc1 | 51 | gfs2_convert to convert a gfs filesystem to gfs2 in-place |
| 4cb947b5 | 52 | mkfs.gfs2 to make a filesystem |
| 720c2fc1 | 53 | ============ ============================================= |