Install guide

Oracle Clusterware. The fencing methods that we recommend for use with Oracle databases, are all
power-based, and have been in the Red Hat Cluster Suite for several releases. Mature, power-based
fencing methods are, indeed, the foundation of any robust cluster.
Most T ier 1 server vendors provide built-in baseboard management controllers (BMC), but they are
called many things (HP iLO, Dell DRAC, Sun ILOM). All BMCs provide network-signaled access to the
server’s power supply. When Red Hat Cluster Suite must fence a node in the cluster, the fencing
process on the node that detected the fault will connect to the other nodes BMC and literally power-off
the server node. This is the most discrete form of fencing, and it the mechanism we use. In this case, we
use HP iLO, which comes standard on all Proliant 300 and 500 series.
Red Hat Cluster Suite also supports levels of fencing for those who find BMC-based fencing insufficient.
Among many other available methods (such as FCP switch port disable), Red Hat Cluster Suite also
supports signaled power distribution units (PDUs). PDUs are also connected to an Ethernet network,
and when engaged for fencing, they cut the power to the server’s power supply, much as the BMC does
on-board. The need to use multi-levels can be necessary because most, if not all, BMC interfaces are
single Ethernet ports. T his could be a single point of failure. Most PDUs also only have 1 network
interface, but combined, these two methods provide redundant power signaling.
Our example will show iLO, and how it can be combined with an APC switched PDU infrastructure.
Red Hat Cluster Suite is typically configured to access the fencing network over the private bonded
fabric, but any network fabric can be subsequently configured if a dedicated (and likely bonded) network
is dedicated just to the fencing network. Our example will access the fencing network over the private,
bonded network.
Chapter 2. Hardware Installation and Configuration
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