Red Hat GFS 6.0 -, Administrator'S Manual

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Chapter 1.
Red Hat GFS Overview
Red Hat GFS is a cluster file system that provides data sharing among Linux-based computers. GFS
provides a single, consistent view of the file system name space across all nodes in a cluster. It allows
applications to install and run without much knowledge of the underlying storage infrastructure. GFS
is fully compliant with the IEEE POSIX interface, allowing applications to perform file operations as
if they were running on a local file system. 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 your storage according to the performance, scalability,
and economic needs of your storage environment.
This chapter provides some very basic, abbreviated information as background to help you understand
GFS. It contains the following sections:
•
Section 1.1 New and Changed Features
•
Section 1.2 Performance, Scalability, and Economy
•
Section 1.3 GFS Functions
•
Section 1.4 GFS Software Subsystems
•
Section 1.5 Before Configuring GFS
1.1. New and Changed Features
This section lists new and changed features included with the initial release of Red Hat GFS 6.0 and
Red Hat GFS 6.0 for Red Hat Enterprise Linux 3 Update 5.
New and Changed Features with the Initial Release of Red Hat GFS 6.0
•
File access control lists (ACLs) and extended file attributes in GFS file systems — This release adds
the capability of setting and getting file ACLs and extended file attributes in a GFS file system. The
Linux commands
setfacl
and
getfacl
set and get ACLs. The Linux commands
setfattr
and
getfattr
set and get file attributes. In addition, this release adds a GFS-specific
mount
command
option,
-o
acl
. The new option allows users to set ACLs. For more information about the
-o
acl
option, refer to Section 9.2 Mounting a File System .
•
Additional fencing agents — This release adds fencing agents for McData Fibre Channel (FC)
switches, Egenera BladeFrame systems, and xCAT (Extreme Cluster Administration Toolkit) clus-
ters.
•
Initialization scripts — This release adds
init.d
scripts for the
pool
,
ccsd
,
lock_gulmd
, and
gfs
modules. For more information about the scripts, refer to
Chapter 12 Using GFS
init.d
Scripts .
•
Configurable node-failure detection parameters — This release adds optional parameters for setting
heartbeat rate and allowed misses. Together, the parameters determine the time interval allowed
without response from a node before the node is considered to have failed. For more information,
refer to Section 6.5 Creating the
cluster.ccs
File .
•
Removal of license mechanism — Previous GFS releases required a license file that defined the
term of use and which GFS features were enabled. This release does not require a license file.