Component Description

The system subrack houses a midplane that provides reliable connections for interface modules and distributes power and signals to inner modules.

Appearance

Figure 4-104 shows the appearance of a system subrack.

Figure 4-104 System subrack

A controller is the core component of a storage system. It processes storage services, receives configuration management commands, saves configuration data, connects to disks, and saves critical data onto coffer disks.

Each controller has one or more built-in disks to store system data. If a power failure occurs, this disk also stores cache data. The built-in disks on different controllers are redundant for each other.

Figure 4-105 shows the appearance and front view of a controller.

Figure 4-105 Front view of a controller

When a controller enclosure is configured with two controllers, assistant cooling modules are installed in the two slots of controllers C and D to help the controller enclosure dissipate heat. Each assistant cooling module has four fans and three fan filler panels.

Figure 4-106 and Figure 4-107 show the appearance and front view of an assistant cooling module.

Figure 4-106 Assistant cooling module

Figure 4-107 Front view of an assistant cooling module

Table 4-37 describes indicators on an assistant cooling module of a powered-on storage system.

Fan modules dissipate heat from the system, allowing the controller enclosure to operate normally at maximum power.

Figure 4-108 and Figure 4-109 show the appearance and front view of a fan module.

Figure 4-108 Fan module

Figure 4-109 Front view of a fan module

Table 4-38 describes the indicator on a fan module of a powered-on storage system.

BBUs supply power to the storage system in the event of an external power supply failure to protect data in the storage system. When the external power supplies are normal, the BBUs are standing by. If a BBU is faulty, it can be isolated without affecting the normal running of the storage system. If a power failure occurs, BBUs ensure that the storage system writes cached data to the built-in disks of the controllers, preventing data loss. After the external power supply resumes, the driver reads data from the built-in disks of the controllers to the cache.

In a system using the lithium batteries, the battery capacity is updated and detected by charging and discharging the batteries. In this way, the problems can be detected in advance that the battery capacity attenuates, the batteries fail to meet the power backup requirements of the system, and thus the data backup fails when the batteries are not used for a long time. Then, the reliability of data protection upon the system power failure can be improved.

Figure 4-110 and Figure 4-111 show the appearance and front view of a BBU.

Figure 4-110 BBU appearance

Figure 4-111 Front view of a BBU

Table 4-39 describes the indicator on a BBU of a storage system that is powered on.

AC power modules are used. They allow the controller enclosure to work properly at maximum power.

Each 4 U controller enclosure has four power modules (PSU 0, PSU 1, PSU 2, and PSU 3). PSU 0 and PSU 1 form a power plane to supply power to controllers A and C, and are redundant of each other. PSU 2 and PSU 3 form the other power plane to supply power to controllers B and D, and are redundant of each other. For reliability purposes, it is recommended that you connect PSU 0 and PSU 2 to one PDU, and PSU 1 and PSU 3 to another PDU.

Figure 4-112 and Figure 4-113 show the appearance of an AC power module.

Figure 4-112 Appearance of an AC power module

Figure 4-113 Front view of an AC power module

Table 4-40 describes the indicator on a power module of a powered-on storage system.

The management module provides management ports including USB ports, management network ports, serial ports, and maintenance network ports.

Figure 4-114 shows the ports on a management module.

Figure 4-114 Management module

Only serial cables can be inserted into the serial ports. Do not insert network cables into the serial ports.

Management network port 1 is reserved and not used.

Table 4-41 describes indicators on a management module of a powered-on storage system.