High-availability cluster design RC18015xs+ and RXD1215sas are specifically designed to work together as a high-availability cluster — requiring two RC18015xs+ and at least one RXD1215sas expansion unit. By combining the two computing servers and multiple storage units into a single high-availability cluster, RC18015xs+ and RXD1215sas deliver unyielding reliability and data availability. With the active/passive structure, services are automatically switched over to one server if the other unexpectedly goes offline, helping your business avoid costly downtime. Massive scalability up to 180 drives Up to fifteen RXD1215sas can be connected to the dual RC18015xs+ computing nodes2, accommodating massive scalability up to 180 drives and maximum raw storage beyond 1PB3. The shared storage model : ADATA XPG SX6000 Lite 512GB PCIe 3D NAND PCIe Internal Solid State Drive tag : NAS