S.M.A.R.T. attributes

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The following table was taken from Wikipedia. For the most up to date information you can go and check out the original resource. The rows marked with red background color representing the critical S.M.A.R.T. attributes. To the information provided on this page applies the Creative Commons Attribution/Share-Alike License.

Rows with red background contain information about the so called 'critical S.M.A.R.T. attributes'.


ID

Hex

Attribute name

Better

Description

01

01

Read Error Rate

smaller

Indicates the rate of hardware read errors that occurred when reading data from a disk surface. A non-zero value indicates a problem with either the disk surface or read/write heads. Note that Seagate drives often report a raw value that is very high even on new drives, and does not thereby indicate a failure.

02

02

Throughput Performance

bigger

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

03

Spin-Up Time

smaller

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

04

04

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.

05

05

Reallocated Sectors Count

smaller

Count of reallocated sectors. When the hard drive finds a read/write/verification error, it marks this 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. This is why, on modern hard disks, "bad blocks" cannot be found while testing the surface – all bad blocks are hidden in reallocated sectors. However, as the number of reallocated sectors increases, the read/write speed tends to decrease. The raw value normally represents a count of the number of bad sectors that have been found and remapped. Thus, the higher the attribute value, the more sectors the drive has had to reallocate.

06

06

Read Channel Margin


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

07

07

Seek Error Rate

smaller

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. More seek errors indicates a worsening condition of a disk’s surface or the mechanical subsystem, or both. Note that Seagate drives often report a raw value that is very high, even on new drives, and this does not normally indicate a failure.

08

08

Seek Time Performance

bigger

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

09

Power-On Hours (POH)

smaller

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.

10

0A

Spin Retry Count

smaller

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

0B

Recalibration Retries

smaller

This attribute indicates the number of times 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

0C

Power Cycle Count


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

13

0D

Soft Read Error Rate

smaller

Uncorrected read errors reported to the operating system.

184

B8

End-to-End error

smaller

This attribute is a part of HPs 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.

187

BB

Reported Uncorrectable Errors

smaller

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

188

BC

Command Timeout

smaller

A number of aborted operations due to HDD timeout. Normally this attribute value should be equal to zero and if you have values far above zero, then most likely you have some serious problems with your power supply or you have an oxidized data cable.

189

BD

High Fly Writes

smaller

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 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.

190

BE

Airflow Temperature

smaller

Airflow temperature on Western Digital HDs

190

BE

Temperature Difference
from 100

bigger

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

191

BF

G-sense error rate

smaller

Frequency of mistakes as a result of impact loads

192

C0

Power-off Retract Count

smaller

Number of times the heads are loaded off the media. Heads can be unloaded without actually powering off. (or Emergency Retract Cycle count – Fujitsu)

193

C1

Load Cycle Count
Load/Unload Cycle Count

smaller

Count of load/unload cycles into head landing zone position.

The typical lifetime rating for laptop (2.5-in) hard drives is 200,000 to 600,000 load cycles. Some laptop drives are programmed to unload the heads whenever there has not been any activity for about five seconds. Many Linux installations write to the filesystem a few times a minute in the background. 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.

194

C2

Temperature

smaller

Current internal temperature.

195

C3

Hardware ECC Recovered

bigger

Time between ECC-corrected errors or number of ECC on-the-fly errors. Sources differ on this point.

196

C4

Reallocation Event Count

smaller

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

197

C5

Current Pending Sector Count

smaller

Number of "unstable" sectors (waiting to be remapped). If the unstable sector is subsequently written or read successfully, this value is decreased and the sector is not remapped. Read errors on the sector will not remap the sector, it will only be remapped on a failed write attempt.

198

C6

Uncorrectable Sector Count

smaller

The total number 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. (or Off-Line Scan Uncorrectable Sector Count – Fujitsu)

199

C7

UltraDMA CRC Error Count

smaller

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

200

C8

Write Error Rate /
Multi-Zone Error Rate

smaller

The total number of errors when writing a sector.

201

C9

Soft Read Error Rate

smaller

Number of off-track errors.

202

CA

Data Address Mark errors

smaller

Number of Data Address Mark errors (or vendor-specific).

203

CB

Run Out Cancel

smaller

Number of ECC errors

204

CC

Soft ECC Correction

smaller

Number of errors corrected by software ECC

205

CD

Thermal Asperity Rate (TAR)

smaller

Number of errors due to high temperaure.

206

CE

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.

207

CF

Spin High Current

smaller

Amount of surge current used to spin up the drive.

208

D0

Spin Buzz


Number of buzz routines needed to spin up the drive due to insufficient power.

209

D1

Offline Seek Performance


Drive’s seek performance during its internal tests.

211

D3

Vibration During Write


Vibration During Write

212

D4

Shock During Write


Shock During Write

220

DC

Disk Shift

smaller

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

221

DD

G-Sense Error Rate

smaller

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

222

DE

Loaded Hours


Time spent operating under data load (movement of magnetic head armature)

223

DF

Load/Unload Retry Count


Number of times head changes position.

224

E0

Load Friction

smaller

Resistance caused by friction in mechanical parts while operating.

225

E1

Load/Unload Cycle Count

smaller

Total number of load cycles

226

E2

Load 'In'-time


Total time of loading on the magnetic heads actuator (time not spent in parking area).

227

E3

Torque Amplification Count

smaller

Number of attempts to compensate for platter speed variations

228

E4

Power-Off Retract Cycle

smaller

The number of times the magnetic armature was retracted automatically as a result of cutting power.

230

E6

GMR Head Amplitude


Amplitude of "thrashing" (distance of repetitive forward/reverse head motion)

231

E7

Temperature

smaller

Drive Temperature

240

F0

Head Flying Hours


Time while head is positioning

250

FA

Read Error Retry Rate

smaller

Number of errors while reading from a disk

254

FE

Free Fall Protection

smaller

Number of "Free Fall Events" detected