Based on kernel version 3.9. Page generated on 2013-05-02 23:06 EST.
1 Global File System 2 ------------------ 3 4 https://fedorahosted.org/cluster/wiki/HomePage 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 14 GFS uses interchangeable inter-node locking mechanisms, the currently 15 supported mechanisms are: 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 22 Lock_dlm depends on user space cluster management systems found 23 at the URL above. 24 25 To use gfs as a local file system, no external clustering systems are 26 needed, simply: 27 28 $ mkfs -t gfs2 -p lock_nolock -j 1 /dev/block_device 29 $ mount -t gfs2 /dev/block_device /dir 30 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 33 and write a cluster.conf as per the documentation. For F17 and above 34 cman has been replaced by the dlm package. 35 36 GFS2 is not on-disk compatible with previous versions of GFS, but it 37 is pretty close. 38 39 The following man pages can be found at the URL above: 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 43 tunegfs2 to manipulate, examine and tune a filesystem 44 gfs2_convert to convert a gfs filesystem to gfs2 in-place 45 mkfs.gfs2 to make a filesystem