The Oracle ZFS Storage Appliance product supports cooperative clustering of appliances. This strategy can be part of an integrated approach to availability enhancement that may also include client-side load balancing, proper site planning, proactive and reactive maintenance and repair, and the single-appliance hardware redundancy built into all appliances.
For tasks related to appliance clustering, see:
Connecting Cluster Cables in Oracle ZFS Storage Appliance Cabling Guide
Upgrading a Standalone Appliance to a Clustered Configuration (BUI)
For a better understanding about appliance clustering, see: