硬盘S.M.A.R.T含义

Legend

Higher raw value is better

Lower raw value is better

Critical: red colored row

Potential indicators of imminent electromechanical failure

ID

Hex

Attribute name

Better

Description

01

0x01

Read Error Rate

^[13]

(Vendor specific raw value.) Stores data related to the rate of hardware read errors that occurred when reading data from a disk surface. The raw value has different structure for different vendors and is often not meaningful as a decimal number.

02

0x02

Throughput Performance

Overall (general) throughput performance of a hard disk drive. If the value of this attribute is decreasing there is a high probability that there is a problem with the disk.

03

0x03

Spin-Up Time

Average time of spindle spin up (from zero RPM to fully operational [millisecs]).

04

0x04

Start/Stop Count

A tally of spindle start/stop cycles. The spindle turns on, and hence the count is increased, both when the hard disk is turned on after having before been turned entirely off (disconnected from power source) and when the hard disk returns from having previously been put to sleep mode.^[14]

05

0x05

Reallocated Sectors Count

Count of reallocated sectors. When the hard drive finds a read/write/verification error, it marks that sector as “reallocated” and transfers data to a special reserved area (spare area). This process is also known as remapping, and reallocated sectors are called “remaps”. The raw value normally represents a count of the bad sectors that have been found and remapped. Thus, the higher the attribute value, the more sectors the drive has had to reallocate. This allows a drive with bad sectors to continue operation, however, a drive which has had any reallocations at all is significantly more likely fail in the near future.^[2] While primarily used as a metric of the life-expectancy of the drive, this number also affects performance. As the count of reallocated sectors increases, the read/write speed tends to become worse because the drive head is forced to seek to the reserved area whenever a remap is accessed. A workaround which will preserve drive speed at the expense of capacity is to create a disk partition over the region which contains remaps and instruct the operating system to not use that partition.

06

0x06

Read Channel Margin

Margin of a channel while reading data. The function of this attribute is not specified.

07

0x07

Seek Error Rate

N/A

(Vendor specific raw value.) Rate of seek errors of the magnetic heads. If there is a partial failure in the mechanical positioning system, then seek errors will arise. Such a failure may be due to numerous factors, such as damage to a servo, or thermal widening of the hard disk. The raw value has different structure for different vendors and is often not meaningful as a decimal number.

08

0x08

Seek Time Performance

Average performance of seek operations of the magnetic heads. If this attribute is decreasing, it is a sign of problems in the mechanical subsystem.

09

0x09

Power-On Hours (POH)

Count of hours in power-on state. The raw value of this attribute shows total count of hours (or minutes, or seconds, depending on manufacturer) in power-on state.^[15]

10

0x0A

Spin Retry Count

Count of retry of spin start attempts. This attribute stores a total count of the spin start attempts to reach the fully operational speed (under the condition that the first attempt was unsuccessful). An increase of this attribute value is a sign of problems in the hard disk mechanical subsystem.

11

0x0B

Recalibration Retries or Calibration Retry Count

This attribute indicates the count that recalibration was requested (under the condition that the first attempt was unsuccessful). An increase of this attribute value is a sign of problems in the hard disk mechanical subsystem.

12

0x0C

Power Cycle Count

This attribute indicates the count of full hard disk power on/off cycles.

13

0x0D

Soft Read Error Rate

Uncorrected read errors reported to the operating system.

183

0xB7

SATA Downshift Error Count

Western Digital and Samsung attribute.

184

0xB8

End-to-End error

This attribute is a part of HP‘s SMART IV technology and it means that after transferring through the cache RAM data buffer the parity data between the host and the hard drive did not match.^[16]

185

0xB9

Head Stability

Western Digital attribute.

186

0xBA

Induced Op-Vibration Detection

Western Digital attribute.

187

0xBB

Reported Uncorrectable Errors

The count of errors that could not be recovered using hardware ECC (see attribute 195).

188

0xBC

Command Timeout

The count of aborted operations due to HDD timeout. Normally this attribute value should be equal to zero and if the value is far above zero, then most likely there will be some serious problems with power supply or an oxidized data cable.^[16]

189

0xBD

High Fly Writes

HDD producers implement a Fly Height Monitor that attempts to provide additional protections for write operations by detecting when a recording head is flying outside its normal operating range. If an unsafe fly height condition is encountered, the write process is stopped, and the information is rewritten or reallocated to a safe region of the hard drive. This attribute indicates the count of these errors detected over the lifetime of the drive.

This feature is implemented in most modern Seagate drives^[1] and some of Western Digital’s drives, beginning with the WD Enterprise WDE18300 and WDE9180 Ultra2 SCSI hard drives, and will be included on all future WD Enterprise products.^[17]

190

0xBE

Airflow Temperature (WDC)

Airflow temperature on Western Digital HDs (Same as temp. [C2], but current value is 50 less for some models. Marked as obsolete.)

190

0xBE

Temperature Difference from 100

Value is equal to (100−temp. °C), allowing manufacturer to set a minimum threshold which corresponds to a maximum temperature.

A note here: smartctl seems to interpret these correctly at least in 5.39.1:

ID# ATTRIBUTE_NAME          FLAG  VALUE WORST THRESH TYPE   UPDATED WHEN_FAILED RAW_VALUE

190 Airflow_Temperature_Cel 0x0022 068   057   045  Old_age Always     –       32 (Lifetime Min/Max 22/33)

notice “raw value” is 32 (the correct airflow temp in celsius) and value is 100-32 = 68.

191

0xBF

G-sense Error Rate

The count of errors resulting from externally-induced shock & vibration.

192

0xC0

Power-off Retract Count or Emergency Retract Cycle Count (Fujitsu)^[18]

Count of times the heads are loaded off the media. Heads can be unloaded without actually powering off.^{[citation needed]}

193

0xC1

Load Cycle Count or Load/Unload Cycle Count (Fujitsu)

Count of load/unload cycles into head landing zone position.^[18]

�vThe typical lifetime rating for laptop (2.5-in) hard drives is 300,000 to 600,000 load cycles.^[19] Some laptop drives are programmed to unload the heads whenever there has not been any activity for about five seconds.^[20] Many Linux installations write to the file system a few times a minute in the background.^[21] As a result, there may be 100 or more load cycles per hour, and the load cycle rating may be exceeded in less than a year.^[22]

194

0xC2

Temperature

Current internal temperature.

195

0xC3

Hardware ECC Recovered

N/A

(Vendor specific raw value.) The raw value has different structure for different vendors and is often not meaningful as a decimal number.

196

0xC4

Reallocation Event Count

Count of remap operations. The raw value of this attribute shows the total count of attempts to transfer data from reallocated sectors to a spare area. Both successful & unsuccessful attempts are counted.^[23]

197

0xC5

Current Pending Sector Count

Count of “unstable” sectors (waiting to be remapped, because of read errors). If an unstable sector is subsequently read successfully, this value is decreased and the sector is not remapped. Read errors on a sector will not remap the sector (since it might be readable later); instead, the drive firmware remembers that the sector needs to be remapped, and remaps it the next time it’s written.^[24]

198

0xC6

Uncorrectable Sector Count or

Offline Uncorrectable or

Off-Line Scan Uncorrectable Sector Count^[18]

The total count of uncorrectable errors when reading/writing a sector. A rise in the value of this attribute indicates defects of the disk surface and/or problems in the mechanical subsystem.

199

0xC7

UltraDMA CRC Error Count

The count of errors in data transfer via the interface cable as determined by ICRC (Interface Cyclic Redundancy Check).

200

0xC8

Multi-Zone Error Rate ^[25]

The count of errors found when writing a sector. The higher the value, the worse the disk’s mechanical condition is.

200

0xC8

Write Error Rate (Fujitsu)

The total count of errors when writing a sector.^[26]

201

0xC9

Soft Read Error Rate or

TA Counter Detected

Count of off-track errors.

202

0xCA

Data Address Mark errors or

TA Counter Increased

Count of Data Address Mark errors (or vendor-specific).^{[citation needed]}

203

0xCB

Run Out Cancel

Count of ECC errors

204

0xCC

Soft ECC Correction

Count of errors corrected by software ECC^{[citation needed]}

205

0xCD

Thermal Asperity Rate (TAR)

Count of errors due to high temperature.^[16]

206

0xCE

Flying Height

Height of heads above the disk surface. A flying height that’s too low increases the chances of a head crash while a flying height that’s too high increases the chances of a read/write error.^{[citation needed]}

207

0xCF

Spin High Current

Amount of surge current used to spin up the drive.^[16]

208

0xD0

Spin Buzz

Count of buzz routines needed to spin up the drive due to insufficient power.^[16]

209

0xD1

Offline Seek Performance

Drive’s seek performance during its internal tests.^[16]

210

0xD2

 ?

(found in a Maxtor 6B200M0 200GB and Maxtor 2R015H1 15GB disks)

211

0xD3

Vibration During Write

Vibration During Write^{[citation needed]}

212

0xD4

Shock During Write

Shock During Write^{[citation needed]}

220

0xDC

Disk Shift

Distance the disk has shifted relative to the spindle (usually due to shock or temperature). Unit of measure is unknown.

221

0xDD

G-Sense Error Rate

The count of errors resulting from externally-induced shock & vibration.

222

0xDE

Loaded Hours

Time spent operating under data load (movement of magnetic head armature)^{[citation needed]}

223

0xDF

Load/Unload Retry Count

Count of times head changes position.^{[citation needed]}

224

0xE0

Load Friction

Resistance caused by friction in mechanical parts while operating.^{[citation needed]}

225

0xE1

Load/Unload Cycle Count

Total count of load cycles^{[citation needed]}

226

0xE2

Load ‘In’-time

Total time of loading on the magnetic heads actuator (time not spent in parking area).^{[citation needed]}

227

0xE3

Torque Amplification Count

Count of attempts to compensate for platter speed variations^{[citation needed]}

228

0xE4

Power-Off Retract Cycle

The count of times the magnetic armature was retracted automatically as a result of cutting power.^{[citation needed]}

230

0xE6

GMR Head Amplitude

Amplitude of “thrashing” (distance of repetitive forward/reverse head motion)^{[citation needed]}

231

0xE7

Temperature

Drive Temperature

232

0xE8

Endurance Remaining

Number of physical erase cycles completed on the drive as a percentage of the maximum physical erase cycles the drive is designed to endure

232

0xE8

Available Reserved Space

Intel SSD reports the number of available reseved space as a percentage of reseved space in a brand new SSD.

233

0xE9

Power-On Hours

Number of hours elapsed in the power-on state.

233

0xE9

Media Wearout Indicator

Intel SSD reports a normalized value of 100 (when the SSD is new) and declines to a minimum value of 1. It decreases while the NAND erase cycles increase from 0 to the maximum-rated cycles.

240

0xF0

Head Flying Hours

Time while head is positioning^{[citation needed]}

240

0xF0

Transfer Error Rate (Fujitsu)

Count of times the link is reset during a data transfer.^[27]

241

0xF1

Total LBAs Written

Total count of LBAs written

242

0xF2

Total LBAs Read

Total count of LBAs read.
Some S.M.A.R.T. utilities will report a negative number for the raw value since in reality it has 48 bits rather than 32.

250

0xFA

Read Error Retry Rate

Count of errors while reading from a disk

254

0xFE

Free Fall Protection

Count of “Free Fall Events” detected ^[28]