Appendix F - Configuring Stretched Cluster and Tiebreaker
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7700 Flash Storage Platform Installation Guide 7.6.3.x
530-0267-00 Rev 02
Note:
If you are prompted to fix any binding conflict, enter
yes
.
From the primary node, use the
enableha
CLI command as shown:
Checking Failover Status
Use the
getfailoverstatus
CLI command to check the current status of failover. This command
also displays all failover settings, including which IP addresses are being monitored for failover. Use
the following command on both nodes:
Enabling a Stretched Cluster
Once an HA cluster has been successfully created, use the
enabledstretchedcluster
CLI
command from the primary node, as shown:
Installing and Configuring Tiebreaker
Tiebreaker is a utility that must be installed on an independent physical or virtual server running
Linux, which is external to the 7700 FSP system, specifically for stretched cluster configurations.
Tiebreaker acts to prevent "split-brain" scenarios that can happen if failover servers ever lose
communication with each other, and if this happens, each one assumes that the other has failed. In
a split-brain scenario, both 7700 Controllers may attempt to write to the same storage, which results
in data inconsistency.
Note:
Tiebreaker is
only
recommended for use in stretched cluster configurations.
The Tiebreaker server monitors 7700 Controllers for failover, and attempts to reset an unresponsive
server so that the partner can safely take over. Tiebreaker monitors up to 10 failover pairs or
stretched clusters, although you cannot use more than one Tiebreaker server to monitor the same
failover pair. Tiebreaker uses SNMP for reporting alerts.
Tiebreaker Requirements
Tiebreaker requires an independent server with the following requirements:
•
Physical or virtual Linux server for installation of an RPM
or
OVA file.
isscli enableha -s 192.168.24.7 -u root -p <password>
-S 192.168.24.130 -U root -P <password> -pcu
root -pcp <password> -ar
isscli getfailoverstatus -s <node name/ip address>
isscli enablestretchedcluster