0001 .. SPDX-License-Identifier: GPL-2.0
0002
0003 ====================
0004 Global File System 2
0005 ====================
0006
0007 GFS2 is a cluster file system. It allows a cluster of computers to
0008 simultaneously use a block device that is shared between them (with FC,
0009 iSCSI, NBD, etc). GFS2 reads and writes to the block device like a local
0010 file system, but also uses a lock module to allow the computers coordinate
0011 their I/O so file system consistency is maintained. One of the nifty
0012 features of GFS2 is perfect consistency -- changes made to the file system
0013 on one machine show up immediately on all other machines in the cluster.
0014
0015 GFS2 uses interchangeable inter-node locking mechanisms, the currently
0016 supported mechanisms are:
0017
0018 lock_nolock
0019 - allows GFS2 to be used as a local file system
0020
0021 lock_dlm
0022 - uses the distributed lock manager (dlm) for inter-node locking.
0023 The dlm is found at linux/fs/dlm/
0024
0025 lock_dlm depends on user space cluster management systems found
0026 at the URL above.
0027
0028 To use GFS2 as a local file system, no external clustering systems are
0029 needed, simply::
0030
0031 $ mkfs -t gfs2 -p lock_nolock -j 1 /dev/block_device
0032 $ mount -t gfs2 /dev/block_device /dir
0033
0034 The gfs2-utils package is required on all cluster nodes and, for lock_dlm, you
0035 will also need the dlm and corosync user space utilities configured as per the
0036 documentation.
0037
0038 gfs2-utils can be found at https://pagure.io/gfs2-utils
0039
0040 GFS2 is not on-disk compatible with previous versions of GFS, but it
0041 is pretty close.
0042
0043 The following man pages are available from gfs2-utils:
0044
0045 ============ =============================================
0046 fsck.gfs2 to repair a filesystem
0047 gfs2_grow to expand a filesystem online
0048 gfs2_jadd to add journals to a filesystem online
0049 tunegfs2 to manipulate, examine and tune a filesystem
0050 gfs2_convert to convert a gfs filesystem to GFS2 in-place
0051 mkfs.gfs2 to make a filesystem
0052 ============ =============================================
