Managing HP Serviceguard A.11.20.20 for Linux, May 2013

Figure 2 Typical Cluster After Failover
After this transfer, the package typically remains on the adoptive node as long the adoptive node
continues running. If you wish, however, you can configure the package to return to its primary
node as soon as the primary node comes back online. Alternatively, you may manually transfer
control of the package back to the primary node at the appropriate time.
Figure 2 (page 21) does not show the power connections to the cluster, but these are important
as well. In order to remove all single points of failure from the cluster, you should provide as many
separate power circuits as needed to prevent a single point of failure of your nodes, disks and
disk mirrors. Each power circuit should be protected by an uninterruptible power source. For more
details, see “Power Supply Planning ” (page 84) section.
Serviceguard is designed to work in conjunction with other high availability products, such as disk
arrays, which use various RAID levels for data protection; and HP-supported uninterruptible power
supplies (UPS), which eliminate failures related to power outage. HP recommends these products;
in conjunction with Serviceguard they provide the highest degree of availability.
1.2 Using Serviceguard for Configuring in an Extended Distance Cluster
Environment
An extended distance cluster (also known as extended campus cluster) is a normal Serviceguard
cluster that has alternate nodes located in different data centers separated by some distance, with
a third location supporting the quorum service. Extended distance clusters are connected using a
high speed cable that guarantees network access between the nodes as long as all guidelines for
disaster recovery architecture are followed. For more information, see the following documents at
http://www.hp.com/go/linux-serviceguard-docs:
• HP Serviceguard Extended Distance Cluster for Linux A.11.20.20 Deployment Guide
• Understanding and Designing Serviceguard Disaster Recovery Architectures
1.2 Using Serviceguard for Configuring in an Extended Distance Cluster Environment 21