Controllers - Fujitsu ETERNUS DX500 S3 Overview

6. Hardware Configurations
Controller Enclosure

Controllers

The controller contains a CPU, cache memory, Bootup and Utility Device (BUD), host interfaces, and drive inter-
face ports. The controller controls all operations in the ETERNUS DX.
An ETERNUS DX has two controllers. This makes it possible for a failed controller to be replaced while the system
is running.
■
CPU
Each controller has one CPU.
■
Cache Memory
Cache memory enables high speed processing by storing frequently used data.
For a SAN environment, the maximum capacity of cache memory for each controller is 32GB for the ETERNUS
DX500 S3 and 64GB for the ETERNUS DX600 S3.
If a cache memory fails, the failed cache memory can be replaced while the system is running.
■
BUD
A BUD is non-volatile memory in which the firmware of an ETERNUS DX is registered. A BUD is used as an area to
back up data in the cache memory if a power failure occurs.
Each controller has one BUD.
If the BUD fails, the failed BUD can be replaced while the system is running.
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FUJITSU Storage ETERNUS DX500 S3/DX600 S3 Hybrid Storage Systems Overview
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