HP Serviceguard How the Cluster Manager Works, Configuring the Cluster, Proxy Daemon cmproxyd

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

.Although all nodes perform some cluster management functions, the cluster coordinator is the central point for inter-node communication.

Configuring the Cluster

The system administrator sets up cluster configuration parameters and does an initial cluster startup; thereafter, the cluster regulates itself without manual intervention in normal operation. Configuration parameters for the cluster include the cluster name and nodes, networking parameters for the cluster heartbeat, cluster lock information, and timing parameters (discussed in the chapter “Planning and

44 Understanding Serviceguard Software Components