Managing Serviceguard A.11.20, March 2013

Cluster WBEM Agent Daemon: cmwbemd
This daemon collaborates with the Serviceguard WBEM provider plug-in module (SGProviders)
and WBEM services cimserver to provide notification (WBEM Indications) of Serviceguard
cluster events to Serviceguard WBEM Indication subscribers that have registered a subscription
with the cimserver. For example, an Indication is sent when the cluster configuration changes,
or when a Serviceguard package has failed.
You must edit /etc/rc.config.d/cmwbemagt to auto-start cmwbemd. Configure cmwbemd to
start before the Serviceguard cluster comes up. You can start and stop cmwbemd with the commands
/sbin/init.d/cmwbemagt start and /sbin/init.d/cmwbemagt stop.
Proxy Daemon: cmproxyd
This daemon is used to proxy or cache Serviceguard configuration data for use by certain
Serviceguard commands running on the local node. This allows these commands to get the data
quicker and removes the burden of responding to certain requests from cmcld.
CFS Components
The HP Serviceguard Storage Management Suite offers additional components for interfacing with
the Veritas Cluster File System on some current versions of HP-UX (see “About Veritas CFS and
CVM from Symantec” (page 23)). Documents for the management suite are posted on http://
www.hp.com/go/hpux-serviceguard-docs.
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 later, or Veritas Cluster File System (CFS), is deployed as part of the
Serviceguard Storage Management 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 Management 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.
• vxfend - When Veritas CFS is deployed as part of the Serviceguard Storage Management
Suite, the I/O fencing daemon vxfend is also included. It implements a quorum-type
functionality for the Veritas Cluster File System. vxfend is controlled by Serviceguard to
synchronize quorum mechanisms.
• cmvxd - The Serviceguard-to-Veritas daemon coordinates the membership information between
Serviceguard and Veritas' Clustered File System product. (Only present when Veritas CFS is
installed.)
• cmvxping- The Serviceguard-to-Veritas daemon activates certain subsystems of the Veritas
Clustered File System product. (Only present when Veritas CFS is installed.)
How the Cluster Manager Works
The cluster manager is used to initialize a cluster, to monitor the health of the cluster, to recognize
node failure if it should occur, and to regulate the re-formation of the cluster when a node joins or
leaves the cluster. The cluster manager operates as a daemon process that runs on each node.
During cluster startup and re-formation activities, one node is selected to act as the cluster coordinator
44 Understanding Serviceguard Software Components