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© 2021 Apacer Technology Inc.

8.2 S.M.A.R.T.

SMART, an acronym for Self-Monitoring, Analysis and Reporting Technology, is an open standard

that allows a hard disk drive to automatically detect its health and report potential failures. When a

failure is recorded by SMART, users can choose to replace the drive to prevent unexpected outage or

data loss. Moreover, SMART can inform users of impending failures while there is still time to perform

proactive actions, such as copy data to another device.

Table 8-4 SMART (02h)

Byte

Length

Description

0

1

Critical Warning

1-2

2

Composite Temperature (PCB Sensor)

3

1

Available Spare

4

1

Available Spare Threshold

5

1

Percentage Used (Average Erase Count / P/E Cycle Count)

6-31

26

Reserved

32-47

16

Data Units Read

48-63

16

Data Units Written

64-79

16

Host Read Commands

80-95

16

Host Write Commands

96-111

16

Controller Busy Time

112-127

16

Power Cycles

128-143

16

Power On Hours

144-159

16

Unsafe Shutdowns

160-175

16

Media and Data Integrity Errors

176-191

16

Number of Error Information Log Entries

192-195

4

Warning Composite Temperature Time

196-199

4

Critical Composite Temperature Time

200-201

2

Temperature Sensor 1: Controller Temperature

202-203

2

Temperature Sensor 2: PCB Temperature

204-205

2

Temperature Sensor 3: NAND Flash Temperature

206-207

2

Temperature Sensor 4

208-209

2

Temperature Sensor 5

210-211

2

Temperature Sensor 6

212-213

2

Temperature Sensor 7

214-215

2

Temperature Sensor 8

216-511

296

Reserved