projects / GitHub / mt8127 / android_kernel_alcatel_ttab.git / blame
| Commit | Line | Data |
|---|---|---|
| e4731420 DT |
1 | Global File System |
| 2 | ------------------ | |
| 3 | ||
| 49f30789 | 4 | https://fedorahosted.org/cluster/wiki/HomePage |
| e4731420 DT |
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 | ||
| 25985edc | 14 | GFS uses interchangeable inter-node locking mechanisms, the currently |
| e9ccb73a | 15 | supported mechanisms are: |
| e4731420 DT |
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 | ||
| e9ccb73a | 22 | Lock_dlm depends on user space cluster management systems found |
| e4731420 DT |
23 | at the URL above. |
| 24 | ||
| 25 | To use gfs as a local file system, no external clustering systems are | |
| 26 | needed, simply: | |
| 27 | ||
| 2fcb4a12 | 28 | $ mkfs -t gfs2 -p lock_nolock -j 1 /dev/block_device |
| e4731420 DT |
29 | $ mount -t gfs2 /dev/block_device /dir |
| 30 | ||
| e9ccb73a SW |
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 | |
| 49f30789 SW |
33 | and write a cluster.conf as per the documentation. For F17 and above |
| 34 | cman has been replaced by the dlm package. | |
| e9ccb73a SW |
35 | |
| 36 | GFS2 is not on-disk compatible with previous versions of GFS, but it | |
| 37 | is pretty close. | |
| e4731420 DT |
38 | |
| 39 | The following man pages can be found at the URL above: | |
| 4cb947b5 AG |
40 | fsck.gfs2 to repair a filesystem |
| 41 | gfs2_grow to expand a filesystem online | |
| 42 | gfs2_jadd to add journals to a filesystem online | |
| 49f30789 | 43 | tunegfs2 to manipulate, examine and tune a filesystem |
| e9ccb73a | 44 | gfs2_convert to convert a gfs filesystem to gfs2 in-place |
| 4cb947b5 | 45 | mkfs.gfs2 to make a filesystem |