I/O enclosures
The I/O enclosure is a bridge between the processor nodes and the customer data, both from the flash drives and the host systems.
The I/O enclosure uses PCIe interfaces to connect I/O adapters in the I/O enclosure to both processor nodes. A PCIe device is an I/O adapter or a processor node.
To improve I/O operations per second (IOPS) and sequential read/write throughput, the I/O enclosure is connected to each processor node with a point-to-point connection.
- Flash interface connectors
- Interface connector that provides PCIe cable connection from the I/O enclosure to the High Performance Flash Enclosure Gen3 enclosure pairs.
- Host adapters
- An I/O enclosure can support up to 16 host ports.
Each of the four 16 or 32 Gbps Fibre Channel ports on a PCIe-attached host adapter can be independently configured to use SCSI/FCP or FICON/zHPF protocols. Both longwave and shortwave adapter versions that support different maximum cable lengths are available. The host-adapter ports can be directly connected to attached hosts systems or storage systems, or connected to a storage area network. SCSI/FCP ports are used for connections between storage systems. SCSI/FCP ports that are attached to a SAN can be used for both host and storage system connections.
The High Performance FICON® Extension (zHPF) protocol can be used by FICON host channels that have zHPF support. The use of zHPF protocols provides a significant reduction in channel usage. This reduction improves I/O input on a single channel and reduces the number of FICON channels that are required to support the workload.