Ds8000 Hardware Specifics; Storage Unit Structure - IBM DS8800 Introduction And Planning Manual

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DS8000 hardware specifics

The DS8000 models offer a high degree of availability and performance through
the use of redundant components that can be replaced while the system is
operating. You can use the DS8000 models with a mix of different operating
systems and clustered and nonclustered variants of the same operating systems.
Contributing to the high degree of availability and reliability are the structure of
the DS8000 storage unit, the host systems it supports, and its processor memory
and processor speeds.

Storage unit structure

The design of the storage unit, which contains the base model and the expansion
models, contributes to the high degree of availability that is associated with the
DS8000 series. The primary components that support high availability within the
storage unit are the storage server, the processor complex, and the rack power
control card.
Storage unit
Storage server
Processor complex
Rack power control card
All DS8000 models include the IBM System Storage Multi-path Subsystem Device
Driver (SDD). The SDD provides load balancing and enhanced data availability
capability in configurations with more than one I/O path between the host server
and the DS8000 series storage unit. Load balancing can reduce or eliminate I/O
bottlenecks that occur when many I/O operations are directed to common devices
using the same I/O path. The SDD can eliminate the single point of failure by
automatically rerouting I/O operations when a path failure occurs.
2. The use of Internet Protocol Version 4 (IPv4) and Internet Protocol
Version 6 (IPv6) are both supported through the HMC ports.
The storage unit contains a storage server and one or more storage (disk)
enclosures that are packaged in one or more racks with associated power
supplies, batteries, and cooling.
The storage server consists of two processor complexes, two or more I/O
enclosures, and a pair of rack power control cards.
A processor complex controls and manages the storage unit to perform the
function of the storage server. The two processor complexes form a
redundant pair such that if either processor complex fails, the remaining
processor complex performs all storage server functions.
A redundant pair of rack power control (RPC) cards coordinate the power
management within the storage unit. The RPC cards are attached to the
service processors in each processor complex, the primary power supplies
in each rack, and indirectly to the fan/sense cards and storage enclosures
in each rack.
Chapter 2. Hardware and features
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