IBM DS8000 manual Rio-G, 2 I/O enclosures

prevent any data loss without operating system or firmware involvement. Non-critical environmental events are also logged and reported.

2.3.1 RIO-G

The RIO-G ports are used for I/O expansion to external I/O drawers. RIO stands for remote I/O. The RIO-G is evolved from earlier versions of the RIO interconnect.

Each RIO-G port can operate at 1 GHz in bidirectional mode and is capable of passing data in each direction on each cycle of the port. It is designed as a high performance self-healing interconnect. The p5 570 provides two external RIO-G ports, and an adapter card adds two more. Two ports on each processor complex form a loop.

Processor

Complex 0

RIO-G ports

I/O enclosure	I/O enclosure
		Processor
	Loop 0	Complex 1
		RIO-G ports
I/O enclosure	I/O enclosure
I/O enclosure	I/O enclosure

Loop 1

I/O enclosure

I/O enclosure

Figure 2-6 DS8000 RIO-G port layout

Figure 2-6illustrates how the RIO-G cabling is laid out in a DS8000 that has eight I/O drawers. This would only occur if an expansion frame were installed. The DS8000 RIO-G cabling will vary based on the model. A two-way DS8000 model will have one RIO-G loop. A four-way DS8000 model will have two RIO-G loops. Each loop will support four disk enclosures.

2.3.2 I/O enclosures

All base models contain I/O enclosures and adapters. The I/O enclosures hold the adapters and provide connectivity between the adapters and the processors. Device adapters and host adapters are installed in the I/O enclosure. Each I/O enclosure has 6 slots. Each slot supports PCI-X adapters running at 64 bit, 133 Mhz. Slots 3 and 6 are used for the device adapters.

The remaining slots are available to install up to four host adapters per I/O enclosure.

Chapter 2. Components 29