Chapter 2 System Management Overview; Firmware Features Overview - HGST Ultrastar Data102 User Manual

User Guide
2 System Management Overview
This chapter provides an overview of the system management features available in the Ultrastar
Data102 through the in-band SAS connections using SG3_utils software, and out-of-band using a
REST interface over HTTPS to access HGST's implementation of the DMTF Redfish API.
2.1 Firmware Features Overview
The enclosure services functionality is compatible with the SES-3 (SES3r14) standard. The
enclosure implements the Standalone Enclosure Services Process model described in the SES
standard. The logical enclosure services process is called the SEP. The SEP operates in a dual
IOM environment. To a host server, the SEP exists as a dual ported SAS device, one port on each
IOM. The firmware on Ultrastar Data102 provides an Active/Active architecture for IOM redundancy.
This allows each IOM to independently report the enclosure status information such as drive power,
fan speed, and LED states. This allows the Ultrastar Data102 to maintain high availability and hot-
swappability. Due to the active/active architecture, commands only need to be executed to one IOM
because either IOM is fully capable of performing all enclosure management tasks. The information
and enclosure status will be synchronized between the two IOMs via the internal SAS links.
The primary expander in each IOM is the only expander that presents a SCSI target, and it is the
main device for gathering information from the system for presentation to hosts. The SEP services
SES control page operations. All control operations follow a synchronous completion model, i.e. the
SEP will send SCSI status only when the requested operation has completed, or to notify the host
that the requested operation cannot be performed. Typical SES control operations include:
• Requesting LED flash patterns
• Recording predicted or known component failures
• Requesting power cycle of one or more drives
• Perform a code download. All firmware in programmable components in the storage subsystem
may be updated via SES.
SES Status
The SEP services SES status pages. All status operations follow a non-blocking completion model,
i.e. the SEP returns the last known status, rather than blocking the completion of the SCSI operation
while doing an immediate polling operation. The SES status is updated every 0.5s. Typical SES
status operations include:
• FRU and drive presence, health information, and entity names
• SAS topology maps
• Report sensor readings: temperatures, fan speeds, voltages, currents, etc.
Autonomous Behavior
The SEP autonomously manages enclosure power and thermal characteristics. This is done
dynamically as needed to stay within the allowed operational envelope of power consumption,
thermal heating, and ambient temperature in the data center. This management can include the use
of one or more mitigating actions:
2. System Management Overview

2.1 Firmware Features Overview

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