HP Serviceguard Quorum Server Version A.04.00 Release Notes, May 2014

Software Depot -> ServiceGuard Quorum Server
The version of the software you download is determined by the operating system you specify on
the download page.
Documentation for This Version
These release notes are shipped with Quorum Server Version A.04.00 and Quorum Server Version
A.04.00.01 for RHEL 6, and published at www.hp.com/go/hpux-serviceguard-docs —>
HP Serviceguard Quorum Server Software.
See also the white paper Arbitration for Data Integrity in Serviceguard Clusters, under Quorum
Server at www.hp.com/go/linux-serviceguard-docs —> HP Serviceguard Quorum Server
Software.
Further Information
The most recent versions of user’s guides, release notes, and white papers about Serviceguard
and related topics are available at http://www.hp.com/go/hpux-serviceguard-docs
-> HP Serviceguard and http://www.hp.com/go/linux-serviceguard-docs.
For a current list of patches, known problems, and workarounds, contact your HP support
representative or go to the appropriate Hewlett-Packard Support Centre website: http://
www.hp.com/go/hpsc.
What is the Quorum Server?
Serviceguard cluster products are specialized facilities for protecting mission-critical applications
from a wide variety of hardware and software failures. The HP Serviceguard Quorum Server
provides arbitration services for Serviceguard clusters when a cluster partition is discovered: must
equal-sized groups of nodes become separated from each other, the Quorum Server allows one
group to achieve quorum and form the cluster, while the other group is denied quorum and cannot
start a cluster.
How the Quorum Server Works?
The Quorum Server runs on an HP-UX or Linux system outside of the cluster for which it is providing
quorum services.
Within the restrictions specified under “System Requirements” (page 7), a Quorum Server running
on either a Linux or an HP-UX system can serve a Serviceguard for Linux cluster, an HP-UX
Serviceguard cluster, or a combination of clusters of both types.
The Quorum Server uses TCP/IP, and listens to connection requests from the Serviceguard nodes
on port # 1238. The server maintains a special area in memory for each cluster; when a node
obtains the cluster lock, this area is marked so that other nodes will recognize the lock as “taken.”
In recent versions of Serviceguard, you can configure more than one connection between the
Quorum Server and each cluster node; see “Compatibility with Serviceguard Versions” (page 9)
and “Using Alternate Subnets” (page 13).
NOTE: The difference between Serviceguard A.11.19 and the earlier versions that support an
alternate-subnet connection is that in the earlier versions, the alternate connections are serialized;
if the first connection fails, the node will attempt to connect to the Quorum Server on the alternate
subnet. In A.11.19 the connections are created in parallel, improving availability: if one connection
fails, the other is still active.
You can make the Quorum Server highly available by configuring it as a Serviceguard package,
so long as the package runs outside the cluster the Quorum Server serves; see “Creating a Package
for the Quorum Server” (page 16).
6 HP Serviceguard Quorum Server Version A.04.00 Release Notes