An Expansion Model (With Front Cover Off) And Its Main Components - IBM DS8000 User Manual

Figure 2 provides a high-level view of the components of an expansion model
(Models 92E, 9AE).
Rack Power
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Figure 2. An expansion model (with front cover off) and its main components
The following notes provide additional information about the labeled components
on Figure 2:
1. The rack power area of each expansion model provides redundant power
supplies (two primary power supplies) and power control cards. If the
expansion model contains I/O enclosures or the extended power line
disturbance (PLD) feature, two or three backup battery assemblies are also
installed to help protect data in the event of a loss of external power.
2. All expansion models allow up to 16 disk enclosures, which contain the disk
drives. In a maximum configuration, each expansion model can hold 256 disk
drives.
3. Expansion models can contain I/O enclosures and adapters if they are the first
expansion models that are attached to a Model 922, 932, 9A2, or 9B2. The
second, third, or fourth expansion model in a 922, 932, 9A2, or 9B2
configuration cannot have I/O enclosures and adapters, nor can any expansion
model that is attached to a Model 921 or 931. If the expansion model contains
I/O enclosures, the enclosures provide connectivity between the adapters and
the processors. The adapters contained in the I/O enclosures can be either
device or host adapters.
Chapter 1. Introduction to IBM System Storage DS8000 series
Disk Enclosures and
Disk Drive Sets
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I/O Enclosures
and Adapters
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