This section provides information and procedures to configure dual-string mediator hosts.
A single disk string consists of a disk enclosure, its physical drives, cables from the enclosure to the node or nodes, and the interface adapter cards. A dual-string disk set includes disks in two disk strings, and is attached to exactly two nodes. If a single disk string in a dual-string disk set fails such that exactly half the Solaris Volume Manager replicas remain available, the disk set will stop functioning. Dual-string mediators are therefore required for all Solaris Volume Manager dual-string disk sets. The use of mediators enables the Oracle Solaris Cluster software to ensure that the most current data is presented in the instance of a single-string failure in a dual-string configuration.
A dual-string mediator, or mediator host, is a cluster node that stores mediator data. Mediator data provides information about the location of other mediators and contains a commit count that is identical to the commit count that is stored in the database replicas. This commit count is used to confirm that the mediator data is in sync with the data in the database replicas.
The following table lists the tasks that you perform to configure dual-string mediator hosts. Complete the procedures in the order that is indicated.