Managing Serviceguard Eighteenth Edition, September 2010

Redundant Power Supplies ...............................................................................................49
Larger Clusters ...................................................................................................................50
Active/Standby Model ..................................................................................................50
Point to Point Connections to Storage Devices ............................................................51
3 Understanding Serviceguard Software Components.....................................................................53
Serviceguard Architecture..................................................................................................53
Serviceguard Daemons.................................................................................................54
Configuration Daemon: cmclconfd..........................................................................55
Cluster Daemon: cmcld............................................................................................55
File Management Daemon: cmfileassistd................................................................56
Syslog Log Daemon: cmlogd...................................................................................56
Cluster Logical Volume Manager Daemon: cmlvmd..............................................56
Cluster Object Manager Daemon: cmomd..............................................................56
Cluster SNMP Agent Daemon: cmsnmpd...............................................................56
Service Assistant Daemon: cmserviced...................................................................57
Quorum Server Daemon: qs....................................................................................57
Network Manager Daemon: cmnetd.......................................................................57
Lock LUN Daemon: cmdisklockd............................................................................58
Utility Daemon: cmlockd.........................................................................................58
Cluster WBEM Agent Daemon: cmwbemd.............................................................58
Proxy Daemon: cmproxyd.......................................................................................58
CFS Components......................................................................................................58
How the Cluster Manager Works ......................................................................................59
Configuring the Cluster ................................................................................................59
Heartbeat Messages ......................................................................................................60
Manual Startup of Entire Cluster .................................................................................61
Automatic Cluster Startup ...........................................................................................61
Dynamic Cluster Re-formation ....................................................................................61
Cluster Quorum to Prevent Split-Brain Syndrome.......................................................62
Cluster Lock ..................................................................................................................62
Lock Requirements..................................................................................................63
Use of a Lock LUN or LVM Lock Disk as the Cluster Lock..........................................63
Single Lock Disk or LUN.........................................................................................64
Dual Lock Disk.........................................................................................................64
Use of the Quorum Server as the Cluster Lock.............................................................65
No Cluster Lock ............................................................................................................66
What Happens when You Change the Quorum Configuration Online.......................66
How the Package Manager Works.....................................................................................67
Package Types...............................................................................................................68
Non-failover Packages.............................................................................................68
Failover Packages.....................................................................................................68
Configuring Failover Packages ..........................................................................69
4 Table of Contents