ZyXEL Communications 4.6 User Manual
Chapter 10 Packages
Media Server User’s Guide
262
10.14.1 S.M.A.R.T Attributes
The following table describes some common S.M.A.R.T. attributes. If a higher or lower raw attribute
value is better, it is indicated in the BETTER column. Since S.M.A.R.T. attributes and their
definitions vary by manufacturer, refer to the hard drive manufacturer for details about the
attributes your hard drive supports.
Table 89
S.M.A.R.T. Attributes
ID
ATTRIBUTE
NAME
NAME
BETTER
DESCRIPTION
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.
problem with the disk surface or the read/write heads.
02
Throughput
Performance
Performance
High
This is the hard drive’s general (overall) throughput performance. A
decreasing value indicates a problem.
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).
spin up (from zero RPM to fully operational).
04
Start/Stop Count
The total number of spindle start and stop cycles.
05
Reallocated
Sectors Count
Sectors Count
Low
Total number of reallocated sectors on the hard drive. When the hard
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.
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
Margin
Margin
This is the margin of a channel when it reads data.
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.
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
Performance
Performance
High
This is an average performance indicator for the seek operations of the
magnetic heads. Mechanical subsystem problems cause this value to
decrease.
magnetic heads. Mechanical subsystem problems cause this value to
decrease.
09
Power-On Hours
(POH)
(POH)
Low
This is how many hours the hard drive has been in a power-on state. The
raw value lists the total number of hours (or minutes, or seconds
depending on the manufacturer).
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.
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
Retries
Retries
High
This is the number of times recalibration was requested when the first
attempt did not succeed. A decrease in this value is an indicator of hard
disk mechanical subsystem problems.
attempt did not succeed. A decrease in this value is an indicator of hard
disk mechanical subsystem problems.
12
Device Power
Cycle Count
Cycle Count
This is the number of times the hard drive has gone through a full power
on and power off.
on and power off.
13
Soft Read Error
Rate
Rate
Low
This is the number of uncorrected read errors the hard drive has
reported. If this is not zero, back up your data.
reported. If this is not zero, back up your data.
190 Airflow
Temperature
Low
This indicates the temperature of the airflow measured by a Western
Digital hard drive.
Digital hard drive.