Chapter 11 Package Management

definitions vary by manufacturer, refer to the hard drive manufacturer for details about the attributes your hard drive supports.

Table 90 S.M.A.R.T. Attributes

ID

ATTRIBUTEBETTER

DESCRIPTION

NAME

 

 

 

01

Read Error Rate

Low

Shows the rate of hardware read errors. If this is not zero, there is a

 

 

 

problem with the disk surface or the read/write heads.

 

 

 

 

02

Throughput

High

This is the hard drive’s general (overall) throughput performance. A

 

Performance

 

decreasing value indicates a problem.

 

 

 

 

03

Spin-Up Time

Low

This is the average number of milliseconds the hard drive took for spindle

 

 

 

spin up (from zero RPM to fully operational).

 

 

 

 

04

Start/Stop Count

 

The total number of spindle start and stop cycles.

 

 

 

 

05

Reallocated

Low

Total number of reallocated sectors on the hard drive. When the hard

 

Sectors Count

 

drive detects a read/write/verification error, it marks the sector as

 

 

 

“reallocated” and transfers the data to a specially reserved (spare) area.

 

 

 

The process is also known as remapping with “reallocated” sectors known

 

 

 

as remaps. The more sectors the hard drive has to reallocate, the slower

 

 

 

read and write speeds become.

 

 

 

 

06

Read Channel

 

This is the margin of a channel when it reads data.

 

Margin

 

 

 

 

 

 

07

Seek Error Rate

Low

This is the rate of the magnetic heads’ seek errors. A failure in the

 

 

 

mechanical positioning system, such as servo damage or a thermal

 

 

 

widening of the disk, results in seek errors. An increasing number of seek

 

 

 

errors indicate the condition of the disk surface and the mechanical

 

 

 

subsystem are worsening.

 

 

 

 

08

Seek Time

High

This is an average performance indicator for the seek operations of the

 

Performance

 

magnetic heads. Mechanical subsystem problems cause this value to

 

 

 

decrease.

 

 

 

 

09

Power-On Hours

Low

This is how many hours the hard drive has been in a power-on state. The

 

(POH)

 

raw value lists the total number of hours (or minutes, or seconds

 

 

 

depending on the manufacturer).

 

 

 

 

10

Spin Retry Count

Low

This is the total number of spin start retry attempts. This is the number of

 

 

 

attempts to spin up to fully operational speed the hard drive has made

 

 

 

when the first attempt did not succeed. An increase in this value is an

 

 

 

indicator of hard disk mechanical subsystem problems.

 

 

 

 

11

Recalibration

High

This is the number of times recalibration was requested when the first

 

Retries

 

attempt did not succeed. A decrease in this value is an indicator of hard

 

 

 

disk mechanical subsystem problems.

 

 

 

 

12

Device Power

 

This is the number of times the hard drive has gone through a full power

 

Cycle Count

 

on and power off.

 

 

 

 

13

Soft Read Error

Low

This is the number of uncorrected read errors the hard drive has

 

Rate

 

reported. If this is not zero, back up your data.

 

 

 

 

190

Airflow

Low

This indicates the temperature of the airflow measured by a Western

 

Temperature

 

Digital hard drive.

 

 

 

 

190

Temperature

High

This indicates the value of 100 - the temperature in degrees Celsius.

 

Difference from

 

Manufacturers can set a minimum threshold that corresponds to a

 

100

 

maximum temperature.

 

 

 

 

191

G-sense error

Low

This is the number of mistakes caused by impact loads.

 

rate

 

 

 

 

 

 

192

Power-off Retract

Low

This is how many times the heads are loaded off the media.

 

Count

 

 

 

 

 

 

193

Load/Unload

Low

This is the number of load and unload cycles into head landing zone

 

Cycle

 

position.

 

 

 

 

276

 

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