5
Hardware forSh ared Storage
5-5
Storage System Hardware
Disk Modules and Module IDs — Rackmount DPE-Based System
Storage Processor (SP)The SP provides the intelligence of the storage system. Using its own
operating system (called Core Software), the SP processes the data
written to or read from the disk modules, and monitors the modules
themselves. An SP consists of a printed-circuit board with memory
modules (DIMMs), and status lights.
For high availability, a storage system can support a second SP. The
second SP provides a second route to a storage system and also lets
the storage system use write caching for enhanced write
performance. Two SPs are required for shared storage.
Figure5-4 Shared Storage Systems
See Chapter 3 for more examples of shared storage.
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SP A
Server Server
SP B
Storage systems
Switch fabric
Adapter
Adapter
Adapter
Adapter
Adapter
Adapter
Server
SP A SP B
Switch fabric
Path 1
Path 2