Controllers
The controller contains a CPU, system memory, Bootup and Utility Device (BUD), host interfaces, and drive
interface ports. The controller controls all operations in the ETERNUS AF.
An ETERNUS AF 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.
■
System Memory
The system memory is a memory module that has the following two types of area.
•
Cache area, which stores frequently used data
•
System area, which stores data for speeding up controller processing
The following table shows the maximum system memory capacity for each controller.
Table 54
Maximum System Memory Capacity for Each Controller
Model
System memory capacity (max.) (per CM)
ETERNUS AF150 S3
16GB
ETERNUS AF250 S3
64GB
ETERNUS AF650 S3
768GB
If the system memory fails, the failed system memory can be replaced while the system is running.
■
BUD
A BUD is non-volatile memory in which the firmware of an ETERNUS AF is registered. A BUD is used as an area to
back up cache data in the system memory if a power failure occurs.
The following table shows the capacity and number of BUDs for each controller.
Table 55
Capacity and Number of BUDs for Each Controller
Model
Capacity
Number of BUDs
ETERNUS AF150 S3
256GB
1
ETERNUS AF250 S3
512GB
2
ETERNUS AF650 S3
512GB
2
If the BUD fails, the failed BUD can be replaced while the system is running.
4. Hardware Configurations
Controller Enclosure
163
Design Guide
Содержание ETERNUS AF S3 Series
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