The data tier cluster enables failover support to improve system availability and fault tolerance.
Two data tier hosts, each managed by a Windows-based failover cluster service
At least one fault-tolerant storage device, the shared cluster storage for database files and transaction logs
Each data tier host is a redundant node in the failover cluster—one active, and one standby (or passive). Host system performance is more critical for the data tier servers, because each host must assume the entire load imposed by the Unwired Server cluster.
All data tier server software must be installed on a local drive, on each data tier host. The data tier software must not be installed on shared cluster storage, or any storage resource that can be managed independent of the data tier host.
All data tier database files and transaction logs must be located on a shared cluster storage device, such as a SAN device with appropriate RAID level.
Each node in the Unwired Server cluster must be able to access the shared data folder, from outside the failover cluster.
Unwired Server processes on each Unwired Server host must have read/write permission in the shared data folder.
The shared data folder can be a parent directory, common to all database files and transaction logs, but it does not have to be.
Each data tier host must be physically connected, by a host bus adapter, to the shared cluster storage device. Each volume that houses a database file system must be accessed as a local disk, on each data tier host.
All data tier services must be configured as cluster resources, managed in the context of a common cluster instance.
To an Unwired Server, data tier hosts in a failover cluster appear to be a single, logical data tier entity.