IBM DS8000 - Manual (Page 134)

112 DS8000 Series: Concepts and Architecture
Figure 6-7 4-way model components
These two figures describe the main components of the I/O controller for the DS8000 series.
The main components include the I/O processors, data cache, internal I/O bus (RIO-G loop),
host adapters, and device adapters. Figure 6-6 on page 111 is a 2-way model and Figure 6-7
is a 4-way model. You can easily see that, if you upgrade from the 2-way model to the 4-way
model, the number of main components doubles within a storage unit.
For further information about performance for the DS8000 series, see Chapter 12,
“Performance considerations” on page 253.
Future Plan
According to the announcement letter, IBM has issued the following Statement of General
Direction:
Future models in the series are planned to provide customers additional flexibility and
scalability. IBM next plans to provide 8-way processors with corresponding scalability from the
2-way and 4-way models currently offered. In addition, physical capacity will be scalable
through increased disk drives within a configuration.
In the 8-way model, the number of main components is four times that of a 2-way model.
The benefit of the DS8000 for scalability
Because the DS8000 series adopts this architecture for the scaling of models, the DS8000
series has the following benefits for scalability:
The DS8000 series is easily scalable for performance and capacity.
The DS8000 series architecture can be easily upgraded.
RIO-G
I/O
Enclosure
Device
Adapter Host
Adapter
Data Cache
and
Persistent
Memory
2-way
processor
Processor Complex
4-way I/O controllers
Hosts
Disks