IBM DS8000 manual Disk subsystem, Rear view, Device adapters

	Two I/O enclosures
Single I/O enclosure	side by side

Front view Rear view

SPCN ports

Redundant	RIO-G
	ports
power supplies

Slots: 1 2 3 4 5 6

Figure 2-7 I/O enclosures

Each I/O enclosure has the following attributes:

￿4U rack-mountable enclosure

￿Six PCI-X slots: 3.3 V, keyed, 133 MHz blind-swap hot-plug

￿Default redundant hot-plug power and cooling devices

￿Two RIO-G and two SPCN ports

2.4Disk subsystem

The DS8000 series offers a selection of Fibre Channel disk drives, including 300 GB drives, allowing a DS8100 to scale up to 115.2 TB of capacity and a DS8300 to scale up to 192 TB of capacity. The disk subsystem consists of three components:

￿First, located in the I/O enclosures are the device adapters. These are RAID controllers that are used by the storage images to access the RAID arrays.

￿Second, the device adapters connect to switched controller cards in the disk enclosures. This creates a switched Fibre Channel disk network.

￿Finally, we have the disks themselves. The disks are commonly referred to as disk drive modules (DDMs).

2.4.1Device adapters

Each DS8000 device adapter (DA) card offers four 2Gbps FC-AL ports. These ports are used to connect the processor complexes to the disk enclosures. The adapter is responsible for managing, monitoring, and rebuilding the RAID arrays. The adapter provides remarkable performance thanks to a new high function/high performance ASIC. To ensure maximum data

30DS8000 Series: Concepts and Architecture