Managing Serviceguard 12th Edition, March 2006

Understanding Serviceguard Software Components
Serviceguard Architecture
Chapter 362
All members of the cluster initiate and maintain a connection to the
quorum server. If the quorum server dies, the Serviceguard nodes will
detect this and then periodically try to reconnect to the quorum server
until it comes back up. If there is a cluster reconfiguration while the
quorum server is down and there is a partition in the cluster that
requires tie-breaking, the reconfiguration will fail.
Network Sensor Assistant daemon cmnetassistd
The network sensor assistant daemon handles addition and deletion of
relocatable package IP(s), for both IPv4 and IPv6 addresses.
CFS Components
The HP Serviceguard Storage Management Suite offers additional
components for interfacing with the VERITAS Cluster File System.
Documents for the management suite are posted on
http://docs.hp.com.
VERITAS CFS components operate directly over Ethernet networks that
connect the nodes within a cluster. Redundant networks are required to
avoid single points of failure.
The VERITAS CFS components are:
• GAB (Group Membership Services/Atomic Broadcast) - When
VERITAS Cluster Volume Manager (CVM) 4.1 or VERITAS Cluster
File System (CFS) is deployed as part of the Serviceguard Storage
Managment Suite bundles, the file /etc/gabtab is automatically
configured and maintained by Serviceguard.
GAB provides membership and messaging for CVM and the CFS.
GAB membership also provides orderly startup and shutdown of the
cluster file system.
• LLT (Low Latency Transport) - When VERITAS CVM or CFS is
deployed as part of the Serviceguard Storage Managment Suite
bundles, the LLT files /etc/llthosts and /etc/llttab are
automatically configured and maintained by Serviceguard.
LLT provides kernel-to-kernel communications and monitors
network communications for CFS.