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Chapter 2. Red Hat Cluster Suite Component Summary

This chapter provides a summary of Red Hat Cluster Suite components and consists of the following sections:

2.1. Cluster Components

Table 2.1, “Red Hat Cluster Suite Software Subsystem Components” summarizes Red Hat Cluster Suite components.

Table 2.1. Red Hat Cluster Suite Software Subsystem Components

CongaluciRemote Management System - Management Station.
ricciRemote Management System - Managed Station.
Cluster Configuration Toolsystem-config-clusterCommand used to manage cluster configuration in a graphical setting.
Cluster Logical Volume Manager (CLVM)clvmdThe daemon that distributes LVM metadata updates around a cluster. It must be running on all nodes in the cluster and will give an error if a node in the cluster does not have this daemon running.
 lvmLVM2 tools. Provides the command-line tools for LVM2.
 system-config-lvmProvides graphical user interface for LVM2.
 lvm.confThe LVM configuration file. The full path is /etc/lvm/lvm.conf.
Cluster Configuration System (CCS)ccs_toolccs_tool is part of the Cluster Configuration System (CCS). It is used to make online updates of CCS configuration files. Additionally, it can be used to upgrade cluster configuration files from CCS archives created with GFS 6.0 (and earlier) to the XML format configuration format used with this release of Red Hat Cluster Suite.
 ccs_testDiagnostic and testing command that is used to retrieve information from configuration files through ccsd.
 ccsdCCS daemon that runs on all cluster nodes and provides configuration file data to cluster software.
 cluster.confThis is the cluster configuration file. The full path is /etc/cluster/cluster.conf.
Cluster Manager (CMAN)cman.koThe kernel module for CMAN.
 cman_toolThis is the administrative front end to CMAN. It starts and stops CMAN and can change some internal parameters such as votes.
 dlm_controldDaemon started by cman init script to manage dlm in kernel; not used by user.
 gfs_controldDaemon started by cman init script to manage gfs in kernel; not used by user.
 group_toolUsed to get a list of groups related to fencing, DLM, GFS, and getting debug information; includes what cman_tool services provided in RHEL 4.
 groupdDaemon started by cman init script to interface between openais/cman and dlm_controld/gfs_controld/fenced; not used by user.<version number>Library for programs that need to interact with cman.ko.
Resource Group Manager (rgmanager)clusvcadmCommand used to manually enable, disable, relocate, and restart user services in a cluster.
 clustatCommand used to display the status of the cluster, including node membership and services running.
 clurgmgrdDaemon used to handle user service requests including service start, service disable, service relocate, and service restart.
 clurmtabdDaemon used to handle Clustered NFS mount tables.
Fencefence_apcFence agent for APC power switch.
 fence_bladecenterFence agent for for IBM Bladecenters with Telnet interface.
 fence_bullpapFence agent for Bull Novascale Platform Administration Processor (PAP) Interface.
 fence_dracFencing agent for Dell Remote Access Card.
 fence_ipmilanFence agent for machines controlled by IPMI (Intelligent Platform Management Interface) over LAN.
 fence_wtiFence agent for WTI power switch.
 fence_brocadeFence agent for Brocade Fibre Channel switch.
 fence_mcdataFence agent for McData Fibre Channel switch.
 fence_vixelFence agent for Vixel Fibre Channel switch.
 fence_sanbox2Fence agent for SANBox2 Fibre Channel switch.
 fence_iloFence agent for HP ILO interfaces (formerly fence_rib).
 fence_rsaI/O Fencing agent for IBM RSA II.
 fence_gnbdFence agent used with GNBD storage.
 fence_scsiI/O fencing agent for SCSI persistent reservations.
 fence_egeneraFence agent used with Egenera BladeFrame system.
 fence_manualFence agent for manual interaction. NOTE This component is not supported for production environments.
 fence_ack_manualUser interface for fence_manual agent.
 fence_nodeA program which performs I/O fencing on a single node.
 fence_xvmI/O Fencing agent for Xen virtual machines.
 fence_xvmdI/O Fencing agent host for Xen virtual machines.
 fence_toolA program to join and leave the fence domain.
 fencedThe I/O Fencing daemon.<version number>Library for Distributed Lock Manager (DLM) support.
GFSgfs.koKernel module that implements the GFS file system and is loaded on GFS cluster nodes.
 gfs_fsckCommand that repairs an unmounted GFS file system.
 gfs_growCommand that grows a mounted GFS file system.
 gfs_jaddCommand that adds journals to a mounted GFS file system.
 gfs_mkfsCommand that creates a GFS file system on a storage device.
 gfs_quotaCommand that manages quotas on a mounted GFS file system.
 gfs_toolCommand that configures or tunes a GFS file system. This command can also gather a variety of information about the file system.
 mount.gfsMount helper called by mount(8); not used by user.
GNBDgnbd.koKernel module that implements the GNBD device driver on clients.
 gnbd_exportCommand to create, export and manage GNBDs on a GNBD server.
 gnbd_importCommand to import and manage GNBDs on a GNBD client.
 gnbd_servA server daemon that allows a node to export local storage over the network.
LVSpulseThis is the controlling process which starts all other daemons related to LVS routers. At boot time, the daemon is started by the /etc/rc.d/init.d/pulse script. It then reads the configuration file /etc/sysconfig/ha/ On the active LVS router, pulse starts the LVS daemon. On the backup router, pulse determines the health of the active router by executing a simple heartbeat at a user-configurable interval. If the active LVS router fails to respond after a user-configurable interval, it initiates failover. During failover, pulse on the backup LVS router instructs the pulse daemon on the active LVS router to shut down all LVS services, starts the send_arp program to reassign the floating IP addresses to the backup LVS router's MAC address, and starts the lvs daemon.
 lvsdThe lvs daemon runs on the active LVS router once called by pulse. It reads the configuration file /etc/sysconfig/ha/, calls the ipvsadm utility to build and maintain the IPVS routing table, and assigns a nanny process for each configured LVS service. If nanny reports a real server is down, lvs instructs the ipvsadm utility to remove the real server from the IPVS routing table.
 ipvsadmThis service updates the IPVS routing table in the kernel. The lvs daemon sets up and administers LVS by calling ipvsadm to add, change, or delete entries in the IPVS routing table.
 nannyThe nanny monitoring daemon runs on the active LVS router. Through this daemon, the active LVS router determines the health of each real server and, optionally, monitors its workload. A separate process runs for each service defined on each real server.
 lvs.cfThis is the LVS configuration file. The full path for the file is /etc/sysconfig/ha/ Directly or indirectly, all daemons get their configuration information from this file.
 Piranha Configuration ToolThis is the Web-based tool for monitoring, configuring, and administering LVS. This is the default tool to maintain the /etc/sysconfig/ha/ LVS configuration file.
 send_arpThis program sends out ARP broadcasts when the floating IP address changes from one node to another during failover.
Quorum DiskqdiskA disk-based quorum daemon for CMAN / Linux-Cluster.
 mkqdiskCluster Quorum Disk Utility.
 qdiskdCluster Quorum Disk Daemon.