1.3. GFS Software Subsystems

Table 1.1, “GFS Software Subsystem Components” summarizes the GFS Software subsystems and their components.

Table 1.1. GFS Software Subsystem Components

Software Subsystem Components Description
GFS gfs.ko Kernel module that implements the GFS file system and is loaded on GFS cluster nodes.
gfs_fsck Command that repairs an unmounted GFS file system.
gfs_grow Command that grows a mounted GFS file system.
gfs_jadd Command that adds journals to a mounted GFS file system.
gfs_mkfs Command that creates a GFS file system on a storage device.
gfs_quota Command that manages quotas on a mounted GFS file system.
gfs_tool Command that configures or tunes a GFS file system. This command can also 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.