IBM Tivoli Monitoring > Version 6.3 Fix Pack 2 > Installation Guides > High Availability Guide for Distributed Systems > Create clusters with monitoring components in a System Automation for Multiplatforms environment > Prepare for the base Tivoli Monitoring cluster with Tivoli System Automation for Multiplatform
IBM Tivoli Monitoring, Version 6.3 Fix Pack 2
Plan for the cluster tiebreaker network device
For a two-node Tivoli System Automation for Multiplatforms cluster, a tiebreaker is required. A tiebreaker is a network device (on Linux, Linux on zSeries , and AIX systems), a SCSI device (on AIX and Linux systems), or an ECKD™ device (on Linux on zSeries systems), which is accessible from both nodes.
The tiebreaker is used when the cluster splits, and the nodes don’t have contact with each other anymore. In this rare case, the tiebreaker makes sure that only one node has communication with the shared resources. This communication protects the resources from concurrent access through both cluster nodes.
- Network tiebreaker
For the Network tiebreaker on Linux, Linux on zSeries, or AIX systems, determine the IP address of the device that is to be used for the tiebreaker. Make sure that this device is accessible from both nodes.
The Network tiebreaker is the easiest to implement because it requires only an IP address that is accessible by both nodes. The Network tiebreaker must also be on the same subnet as both nodes.
(To use the Network tiebreaker, use the net parameter for the itm6/BuildScripts/mkitmcluster.sh script.)
- SCSI tiebreaker on Linux systems
For the SCSI tiebreaker on Linux, for both nodes, the following parameters for the SCSI device are required:
SCSI Host number
Channel number
ID number
LUN number
To determine the values, run (on both nodes):
dmesg | grep ‘Attached scsi disk’
If this command doesn’t return anything (because the messages might have been overwritten in the buffer), then run this command:
cat /proc/scsi/scsi
The output shows the exact parameters of each SCSI device attached to the system.
The SCSI device must be accessible to both nodes.
(To use the SCSI tiebreaker, use the scsi parameter for the itm6/BuildScripts/mkitmcluster.sh script.)
- SCSI tiebreaker on AIX systems
For the SCSI tiebreaker on AIX, you need the name of the hard disk device (/dev/hdiskX). The hard disk device must support the SCSI protocol.
Drives attached via Fiber Channel, iSCSI, and Serial Storage Architecture support the SCSI protocol, and can be used as tiebreaker devices.
IDE drives do not support the SCSI protocol, and can not be used as tiebreaker devices.
Use the following command to list all physical volumes:
lspv
Use the following command to verify that the specific drive supports SCSI:
lsdev -C -l <devicename>
(To use the Disk tiebreaker, use the disk parameter for the itm6/BuildScripts/mkitmcluster.sh script.)
- ECKD tiebreaker on Linux on zSeries systems
For the ECKD tiebreaker on Linux on zSeries, you need the ECKD device number. To gather this information, run:
cat /proc/dasd/devices
The ECKD device number is in the first column.
(To use the ECKD tiebreaker, use the eckd parameter for the itm6/BuildScripts/mkitmcluster.sh script.)
For further information, see the IBM Tivoli System Automation for Multiplatforms Base Component Administrator’s Guide and the Reliable Scalable Cluster Technology (RSCT) Administrator’s Guide.
Parent topic:
Prepare for the base Tivoli Monitoring cluster with Tivoli System Automation for Multiplatform