Managing Serviceguard 14th Edition, June 2007

Understanding Serviceguard Software Components
Serviceguard Architecture
Chapter 360
Utility Daemon: cmlockd
Runs on every node on which cmcld is running (though currently not
actually used by Serviceguard on HP-UX systems).
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” on page 29). 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 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.)