49f30789fc
Various items were a bit out of date, so this is a refresh to the latest info. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
45 lines
1.8 KiB
Text
45 lines
1.8 KiB
Text
Global File System
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https://fedorahosted.org/cluster/wiki/HomePage
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GFS is a cluster file system. It allows a cluster of computers to
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simultaneously use a block device that is shared between them (with FC,
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iSCSI, NBD, etc). GFS reads and writes to the block device like a local
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file system, but also uses a lock module to allow the computers coordinate
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their I/O so file system consistency is maintained. One of the nifty
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features of GFS is perfect consistency -- changes made to the file system
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on one machine show up immediately on all other machines in the cluster.
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GFS uses interchangeable inter-node locking mechanisms, the currently
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supported mechanisms are:
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lock_nolock -- allows gfs to be used as a local file system
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lock_dlm -- uses a distributed lock manager (dlm) for inter-node locking
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The dlm is found at linux/fs/dlm/
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Lock_dlm depends on user space cluster management systems found
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at the URL above.
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To use gfs as a local file system, no external clustering systems are
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needed, simply:
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$ mkfs -t gfs2 -p lock_nolock -j 1 /dev/block_device
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$ mount -t gfs2 /dev/block_device /dir
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If you are using Fedora, you need to install the gfs2-utils package
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and, for lock_dlm, you will also need to install the cman package
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and write a cluster.conf as per the documentation. For F17 and above
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cman has been replaced by the dlm package.
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GFS2 is not on-disk compatible with previous versions of GFS, but it
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is pretty close.
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The following man pages can be found at the URL above:
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fsck.gfs2 to repair a filesystem
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gfs2_grow to expand a filesystem online
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gfs2_jadd to add journals to a filesystem online
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tunegfs2 to manipulate, examine and tune a filesystem
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gfs2_convert to convert a gfs filesystem to gfs2 in-place
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mkfs.gfs2 to make a filesystem
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