Installation guide

160 Appendix A:Supplementary Hardware Information
Note
It has been observed that the Master Switch may become unresponsive
when placed on networks which have high occurrences of broadcast or
multi-cast packets. In these cases, isolate the power switch to a private
subnet.
• APC Serial On/Off Switch (partAP9211): http://www.apc.com
Note
This switch type does not provide a means for the cluster to query its sta-
tus. Therefore the cluster always assumes it is connected and operational.
A.1.6 Setting up Power Switch type None
It is possible to configure a cluster that does not include any power switch functionality. As described
in Section 2.1.3, Choosing the Type of Power Controller, configuring a cluster without any power
switch provisions is not recommended due to data corruption vulnerabilities under certain failover
scenarios.
In order to setup a cluster that does not include any power switch provisions, simply select the type
NONE when prompted for power switch type from the cluconfig utility.
Note
Usage of power switch type NONE is discouraged because it does not protect
data integrity in the event of system hang. If your cluster configuration does
not include hardware power switches, then the software watchdog type is
recommended.
A.2 SCSI Bus Configuration Requirements
SCSI buses must adhere to a number of configuration requirements in order to operate correctly. Fail-
ure to adhere to these requirements will adversely affect cluster operation and application and data
availability.
The following are
SCSI bus configuration requirements: