Red Hat GLOBAL FILE SYSTEM 4.7, Manual

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Software Subsystem Components Description
gather a variety of information about the
file system.
lock_harness.ko
Implements a pluggable lock module
interface for GFS that allows for a variety
of locking mechanisms to be used (for
example, the DLM lock module,
lock_dlm.ko
).
lock_dlm.ko
A lock module that implements DLM
locking for GFS. It plugs into the lock
harness,
lock_harness.ko
and
communicates with the DLM lock
manager in Red Hat Cluster Suite.
lock_gulm.ko
A lock module that implements GULM
locking for GFS. It plugs into the lock
harness,
lock_harness.ko
and
communicates with the GULM lock
manager in Red Hat Cluster Suite.
lock_nolock.ko
A lock module for use when GFS is used
as a local file system only. It plugs into
the lock harness,
lock_harness.ko
and
provides local locking.
Table 1.1. GFS Software Subsystem Components
4. Before Setting Up GFS
Before you install and set up GFS, note the following key characteristics of your GFS file
systems:
Number of file systems
Determine how many GFS file systems to create initially. (More file systems can be added
later.)
File-system name
Determine a unique name for each file system. Each file-system name is required in the
form of a parameter variable. For example, this book uses file-system names
gfs1
and
gfs2
in some example procedures.
Journals
Determine the number of journals for your GFS file systems. One journal is required for
each node that mounts a GFS file system. Make sure to account for additional journals
needed for future expansion.
Chapter 1. GFS Overview
6