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Diffstat (limited to 'Documentation/filesystems')
| -rw-r--r-- | Documentation/filesystems/gfs2.txt | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/Documentation/filesystems/gfs2.txt b/Documentation/filesystems/gfs2.txt new file mode 100644 index 000000000000..593004b6bbab --- /dev/null +++ b/Documentation/filesystems/gfs2.txt @@ -0,0 +1,43 @@ +Global File System +------------------ + +http://sources.redhat.com/cluster/ + +GFS is a cluster file system. It allows a cluster of computers to +simultaneously use a block device that is shared between them (with FC, +iSCSI, NBD, etc). GFS reads and writes to the block device like a local +file system, but also uses a lock module to allow the computers coordinate +their I/O so file system consistency is maintained. One of the nifty +features of GFS is perfect consistency -- changes made to the file system +on one machine show up immediately on all other machines in the cluster. + +GFS uses interchangable inter-node locking mechanisms. Different lock +modules can plug into GFS and each file system selects the appropriate +lock module at mount time. Lock modules include: + + lock_nolock -- allows gfs to be used as a local file system + + lock_dlm -- uses a distributed lock manager (dlm) for inter-node locking + The dlm is found at linux/fs/dlm/ + +In addition to interfacing with an external locking manager, a gfs lock +module is responsible for interacting with external cluster management +systems. Lock_dlm depends on user space cluster management systems found +at the URL above. + +To use gfs as a local file system, no external clustering systems are +needed, simply: + + $ mkfs -t gfs2 -p lock_nolock -j 1 /dev/block_device + $ mount -t gfs2 /dev/block_device /dir + +GFS2 is not on-disk compatible with previous versions of GFS. + +The following man pages can be found at the URL above: + gfs2_fsck to repair a filesystem + gfs2_grow to expand a filesystem online + gfs2_jadd to add journals to a filesystem online + gfs2_tool to manipulate, examine and tune a filesystem + gfs2_quota to examine and change quota values in a filesystem + mount.gfs2 to help mount(8) mount a filesystem + mkfs.gfs2 to make a filesystem |