Global File System ------------------ https://fedorahosted.org/cluster/wiki/HomePage 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 interchangeable inter-node locking mechanisms, the currently supported mechanisms are: 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/ 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 If you are using Fedora, you need to install the gfs2-utils package and, for lock_dlm, you will also need to install the cman package and write a cluster.conf as per the documentation. For F17 and above cman has been replaced by the dlm package. GFS2 is not on-disk compatible with previous versions of GFS, but it is pretty close. The following man pages can be found at the URL above: fsck.gfs2 to repair a filesystem gfs2_grow to expand a filesystem online gfs2_jadd to add journals to a filesystem online tunegfs2 to manipulate, examine and tune a filesystem gfs2_convert to convert a gfs filesystem to gfs2 in-place mkfs.gfs2 to make a filesystem