Red Hat CLUSTER SUITE - FOR RHEL 4 Overview page 25

Chapter 1. Red Hat Cluster Suite Overview
1.5. Red Hat GFS
Red Hat GFS is a cluster file system that allows a cluster of nodes to simultaneously access
a block device that is shared among the nodes. GFS is a native file system that interfaces
directly with the VFS layer of the Linux kernel file-system interface. GFS employs dis-
tributed metadata and multiple journals for optimal operation in a cluster. To maintain file
system integrity, GFS uses a lock manager to coordinate I/O. When one node changes data
on a GFS file system, that change is immediately visible to the other cluster nodes using
that file system.
Using Red Hat GFS, you can achieve maximum application uptime through the following
benefits:
Simplifying your data infrastructure
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Install and patch applications once for the entire cluster.
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Eliminates the need for redundant copies of application data (duplication).
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Enables concurrent read/write access to data by many clients.
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Simplifies backup and disaster recovery (only one file system to back up or recover).
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Maximize the use of storage resources; minimize storage administration costs.
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Manage storage as a whole instead of by partition.
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Decrease overall storage needs by eliminating the need for data replications.
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Scale the cluster seamlessly by adding servers or storage on the fly.
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No more partitioning storage through complicated techniques.
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Add servers to the cluster on the fly by mounting them to the common file system.
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Nodes that run Red Hat GFS are configured and managed with Red Hat Cluster Suite con-
figuration and management tools. Volume management is managed through CLVM (Clus-
ter Logical Volume Manager). Red Hat GFS provides data sharing among GFS nodes in
a Red Hat cluster. GFS provides a single, consistent view of the file-system name space
across the GFS nodes in a Red Hat cluster. GFS allows applications to install and run with-
out much knowledge of the underlying storage infrastructure. Also, GFS provides features
that are typically required in enterprise environments, such as quotas, multiple journals,
and multipath support.
GFS provides a versatile method of networking storage according to the performance, scal-
ability, and economic needs of your storage environment. This chapter provides some very
basic, abbreviated information as background to help you understand GFS.
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