1*4882a593Smuzhiyun.. SPDX-License-Identifier: GPL-2.0 2*4882a593Smuzhiyun 3*4882a593Smuzhiyun================== 4*4882a593SmuzhiyunGlobal File System 5*4882a593Smuzhiyun================== 6*4882a593Smuzhiyun 7*4882a593Smuzhiyunhttps://fedorahosted.org/cluster/wiki/HomePage 8*4882a593Smuzhiyun 9*4882a593SmuzhiyunGFS is a cluster file system. It allows a cluster of computers to 10*4882a593Smuzhiyunsimultaneously use a block device that is shared between them (with FC, 11*4882a593SmuzhiyuniSCSI, NBD, etc). GFS reads and writes to the block device like a local 12*4882a593Smuzhiyunfile system, but also uses a lock module to allow the computers coordinate 13*4882a593Smuzhiyuntheir I/O so file system consistency is maintained. One of the nifty 14*4882a593Smuzhiyunfeatures of GFS is perfect consistency -- changes made to the file system 15*4882a593Smuzhiyunon one machine show up immediately on all other machines in the cluster. 16*4882a593Smuzhiyun 17*4882a593SmuzhiyunGFS uses interchangeable inter-node locking mechanisms, the currently 18*4882a593Smuzhiyunsupported mechanisms are: 19*4882a593Smuzhiyun 20*4882a593Smuzhiyun lock_nolock 21*4882a593Smuzhiyun - allows gfs to be used as a local file system 22*4882a593Smuzhiyun 23*4882a593Smuzhiyun lock_dlm 24*4882a593Smuzhiyun - uses a distributed lock manager (dlm) for inter-node locking. 25*4882a593Smuzhiyun The dlm is found at linux/fs/dlm/ 26*4882a593Smuzhiyun 27*4882a593SmuzhiyunLock_dlm depends on user space cluster management systems found 28*4882a593Smuzhiyunat the URL above. 29*4882a593Smuzhiyun 30*4882a593SmuzhiyunTo use gfs as a local file system, no external clustering systems are 31*4882a593Smuzhiyunneeded, simply:: 32*4882a593Smuzhiyun 33*4882a593Smuzhiyun $ mkfs -t gfs2 -p lock_nolock -j 1 /dev/block_device 34*4882a593Smuzhiyun $ mount -t gfs2 /dev/block_device /dir 35*4882a593Smuzhiyun 36*4882a593SmuzhiyunIf you are using Fedora, you need to install the gfs2-utils package 37*4882a593Smuzhiyunand, for lock_dlm, you will also need to install the cman package 38*4882a593Smuzhiyunand write a cluster.conf as per the documentation. For F17 and above 39*4882a593Smuzhiyuncman has been replaced by the dlm package. 40*4882a593Smuzhiyun 41*4882a593SmuzhiyunGFS2 is not on-disk compatible with previous versions of GFS, but it 42*4882a593Smuzhiyunis pretty close. 43*4882a593Smuzhiyun 44*4882a593SmuzhiyunThe following man pages can be found at the URL above: 45*4882a593Smuzhiyun 46*4882a593Smuzhiyun ============ ============================================= 47*4882a593Smuzhiyun fsck.gfs2 to repair a filesystem 48*4882a593Smuzhiyun gfs2_grow to expand a filesystem online 49*4882a593Smuzhiyun gfs2_jadd to add journals to a filesystem online 50*4882a593Smuzhiyun tunegfs2 to manipulate, examine and tune a filesystem 51*4882a593Smuzhiyun gfs2_convert to convert a gfs filesystem to gfs2 in-place 52*4882a593Smuzhiyun mkfs.gfs2 to make a filesystem 53*4882a593Smuzhiyun ============ ============================================= 54