Self-Monitoring, Analysis and Reporting Technology: differenze tra le versioni
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Riga 25:
Ogni produttore definisce un insieme di attributi S.M.A.R.T. e imposta i valori di soglia che non dovrebbero essere superati durante un normale funzionamento. La scala di valori che un attributo può assumere varia da 1 a 253 (1 indica il funzionamento peggiore e 253 quello migliore). A seconda del produttore, gli attributi con valore di circa 100 o 200 saranno scelti come valori "normali".
I produttori potrebbero non concordare sulle definizioni degli attributi e sulle unità di misura.
<!--{| class="wikitable" align="center"
! colspan = "4" | Legend
|-
| <center>[[Image:Green Arrow Up.svg|12px]] || <center>Higher raw value is better || <center>[[Image:Green Arrow Down.svg|12px]] || <center>Lower raw value is better
|-
| colspan = "2" style="width: 50%; background-color: #ffa07a" | <center>'''Critical''' || colspan = "2" style="width: 50%; background-color: #ffa07a" | Potential indicators of imminent electromechanical failure
|}
{| class="wikitable" summary="Overview of known S.M.A.R.T. attributes and their description"
! ID || Hex || Attribute name || Better || Description
|- style="background-color: #ffa07a"
| 01 || 01 || nowrap | '''Read Error Rate''' || <center>[[Image:Green Arrow Down.svg|12px]] || 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. Do note that Seagate drives often report a raw value, that does not mean it is in failure and show high value even as a new drive.
|-
| 02 || 02 || nowrap | '''Throughput Performance''' || <center>[[Image:Green Arrow Up.svg|12px]] || 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 || nowrap | '''Spin-Up Time''' || <center>[[Image:Green Arrow Down.svg|12px]] || Average time of spindle spin up (from zero RPM to fully operational [millisec]).
|-
| 04 || 04 || nowrap | '''Start/Stop Count''' || || A tally of spindle start/stop cycles.
|-style="background-color: #ffa07a"
| 05 || 05 || nowrap | '''Reallocated Sectors Count''' || <center>[[Image:Green Arrow Down.svg|12px]] || 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, the more sectors that are reallocated, the more read/write speed will decrease. A decrease in the attribute value indicates bad sectors.
|-
| 06 || 06 || nowrap | '''Read Channel Margin''' || || Margin of a channel while reading data. The function of this attribute is not specified.
|-
| 07 || 07 || nowrap | '''Seek Error Rate ''' || <center>[[Image:Green Arrow Down.svg|12px]] || Rate of seek errors of the magnetic heads. If there is a failure in the mechanical positioning system, a servo damage or a thermal widening of the hard disk, seek errors arise. More seek errors indicates a worsening condition of a disk surface and the mechanical subsystem.
|-
| 08 || 08 || nowrap | '''Seek Time Performance ''' || <center>[[Image:Green Arrow Up.svg|12px]] || 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 || nowrap | '''Power-On Hours (POH)''' || <center>[[Image:Green Arrow Down.svg|12px]] || 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.
|- style="background-color: #ffa07a"
| 10 || 0A || nowrap | '''Spin Retry Count''' || <center>[[Image:Green Arrow Down.svg|12px]] || 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 || nowrap | '''Recalibration Retries''' || <center>[[Image:Green Arrow Up.svg|12px]] || This attribute indicates the number of times recalibration was requested (under the condition that the first attempt was unsuccessful). A decrease of this attribute value is a sign of problems in the hard disk mechanical subsystem.
|-
| 12 || 0C || nowrap | '''Device Power Cycle Count''' || || This attribute indicates the count of full hard disk power on/off cycles.
|-
| 13 || 0D || nowrap | '''Soft Read Error Rate''' || <center>[[Image:Green Arrow Down.svg|12px]] || Uncorrected read errors reported to the operating system. If the value is non-zero, you should back up your data.
|-
| 190 || BE || nowrap | '''Airflow Temperature (WDC)''' || <center>[[Image:Green Arrow Down.svg|12px]] || Airflow temperature on Western Digital HDs (Same as temp. (C2), but current value is 50 less for some models. Marked as obsolete.)
|-
| 190 || BE || nowrap | '''Temperature Difference from 100''' || <center>[[Image:Green Arrow Up.svg|12px]] || Value is equal to (100 - temp °C), allowing manufacturer to set a minimum threshold which corresponds to a maximum temperature.
(Seagate only?){{Fact|date=April 2007}}<br>
Seagate ST910021AS: Verified Present{{Fact|date=April 2007}}<br>
Seagate ST3802110A: Verified Present 2007-02-13{{Fact|date=April 2007}}<br>
Seagate ST980825AS: Verified Present 2007-04-05{{Fact|date=April 2007}}<br>
Seagate ST3320620AS: Verified Present 2007-04-23{{Fact|date=April 2007}}<br>
Seagate ST3500641AS: Verified Present 2007-06-12{{Fact|date=June 2007}}<br>
Seagate ST3250824AS: Verified Present 2007-08-07{{Fact|date=August 2007}}<br>
Seagate ST31000340AS: Verified Present 2008-02-05{{Fact|date=February 2008}}<br>
Seagate ST3160211AS: Verified Present 2008-06-12{{Fact|date=June 2008}}<br>
Seagate ST3320620AS: Verified Present 2008-06-12{{Fact|date=June 2008}}<br>
Seagate ST3400620AS: Verified Present 2008-06-12{{Fact|date=June 2008}}<br>
Samsung HD501LJ: Verified Present under name "Airflow Temperature" 2008-03-02{{Fact|date=March 2008}}<br>
|-
| 191 || BF || nowrap | '''G-sense error rate''' || <center>[[Image:Green Arrow Down.svg|12px]] || Frequency of mistakes as a result of impact loads{{Fact|date=April 2007}}
|-
| 192 || C0 || nowrap | '''Power-off Retract Count''' || <center>[[Image:Green Arrow Down.svg|12px]] || Number of times the heads are loaded off the media. Heads can be unloaded without actually powering off.{{Fact|date=April 2007}} (or Emergency Retract Cycle count - Fujitsu){{Fact|date=April 2007}}
|-
| 193 || C1 || nowrap | '''Load/Unload Cycle''' || <center>[[Image:Green Arrow Down.svg|12px]] || Count of load/unload cycles into head landing zone position. {{Fact|date=April 2007}}
|-
| 194 || C2 || nowrap | '''Temperature''' || <center>[[Image:Green Arrow Down.svg|12px]] || Current internal temperature.
|-
| 195 || C3 || nowrap | '''Hardware ECC Recovered''' || <center>[[Image:Green Arrow Up.svg|12px]] || Time between ECC-corrected errors.
|-style="background-color: #ffa07a"
| 196 || C4 || nowrap | '''Reallocation Event Count''' || <center>[[Image:Green Arrow Down.svg|12px]] || 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.
|-style="background-color: #ffa07a"
| 197 || C5 || nowrap | '''Current Pending Sector Count''' || <center>[[Image:Green Arrow Down.svg|12px]] || 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. This can be problematic to test because cached writes will not remap the sector, only direct I/O writes to the disk.
|-style="background-color: #ffa07a"
| 198 || C6 || nowrap | '''Uncorrectable Sector Count''' || <center>[[Image:Green Arrow Down.svg|12px]] || 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.
|-
| 199 || C7 || nowrap | '''UltraDMA CRC Error Count''' || <center>[[Image:Green Arrow Down.svg|12px]] || The number of errors in data transfer via the interface cable as determined by ICRC (Interface Cyclic Redundancy Check).
|-
| 200 || C8 || nowrap | '''Write Error Rate / <br/> Multi-Zone Error Rate''' || <center>[[Image:Green Arrow Down.svg|12px]] || The total number of errors when writing a sector.
|-style="background-color: #ffa07a"
| 201 || C9 || nowrap | '''Soft Read Error Rate''' || <center>[[Image:Green Arrow Down.svg|12px]] || Number of off-track errors. If non-zero, make a backup.
|-
| 202 || CA || nowrap | '''Data Address Mark errors''' || <center>[[Image:Green Arrow Down.svg|12px]] || Number of Data Address Mark errors (or vendor-specific).{{Fact|date=April 2007}}
|-
| 203 || CB || nowrap | '''Run Out Cancel''' || <center>[[Image:Green Arrow Down.svg|12px]] || Number of ECC errors
|-
| 204 || CC || nowrap | '''Soft ECC Correction''' || <center>[[Image:Green Arrow Down.svg|12px]] || Number of errors corrected by software ECC{{Fact|date=April 2007}}
|-
| 205 || CD || nowrap | '''Thermal Asperity Rate (TAR)''' || <center>[[Image:Green Arrow Down.svg|12px]] || Number of thermal asperity errors.{{Fact|date=April 2007}}
|-
| 206 || CE || nowrap | '''Flying Height''' || ? || Height of heads above the disk surface.{{Fact|date=April 2007}}
|-
| 207 || CF || nowrap | '''Spin High Current''' || ? || Amount of high current used to spin up the drive.{{Fact|date=April 2007}}
|-
| 208 || D0 || nowrap | '''Spin Buzz''' || ? || Number of buzz routines to spin up the drive{{Fact|date=April 2007}}
|-
| 209 || D1 || nowrap | '''Offline Seek Performance''' || ? || Drive’s seek performance during offline operations{{Fact|date=April 2007}}
|-style="background-color: #ffa07a"
| 220 || DC || nowrap | '''Disk Shift''' || <center>[[Image:Green Arrow Down.svg|12px]] || Distance the disk has shifted relative to the spindle (usually due to shock). Unit of measure is unknown.
|-
| 221 || DD || nowrap | '''G-Sense Error Rate''' || <center>[[Image:Green Arrow Down.svg|12px]] || The number of errors resulting from externally-induced shock & vibration.
|-
| 222 || DE || nowrap | '''Loaded Hours''' || ? || Time spent operating under data load (movement of magnetic head armature){{Fact|date=April 2007}}
|-
| 223 || DF || nowrap | '''Load/Unload Retry Count''' || ? || Number of times head changes position.{{Fact|date=April 2007}}
|-
| 224 || E0 || nowrap | '''Load Friction''' || <center>[[Image:Green Arrow Down.svg|12px]] || Resistance caused by friction in mechanical parts while operating.{{Fact|date=April 2007}}
|-
| 225 || E1 || nowrap | '''Load/Unload Cycle Count''' || <center>[[Image:Green Arrow Down.svg|12px]] || Total number of load cycles{{Fact|date=April 2007}}
|-
| 226 || E2 || nowrap | '''Load 'In'-time''' || ? || Total time of loading on the magnetic heads actuator (time not spent in parking area).{{Fact|date=April 2007}}
|-
| 227 || E3 || nowrap | '''Torque Amplification Count''' || <center>[[Image:Green Arrow Down.svg|12px]] || Number of attempts to compensate for platter speed variations{{Fact|date=April 2007}}
|-
| 228 || E4 || nowrap | '''Power-Off Retract Cycle''' || <center>[[Image:Green Arrow Down.svg|12px]] || The number of times the magnetic armature was retracted automatically as a result of cutting power.{{Fact|date=April 2007}}
|-
| 230 || E6 || nowrap | '''GMR Head Amplitude''' || ? || Amplitude of "thrashing" (distance of repetitive forward/reverse head motion){{Fact|date=April 2007}}
|-
| 231 || E7 || nowrap | '''Temperature''' || <center>[[Image:Green Arrow Down.svg|12px]] || Drive Temperature
|-
| 240 || F0 || nowrap | '''Head Flying Hours''' || ? || Time while head is positioning{{Fact|date=April 2007}}
|-
| 250 || FA || nowrap | '''Read Error Retry Rate''' || <center>[[Image:Green Arrow Down.svg|12px]] || Number of errors while reading from a disk
|}
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==Bibliografia==
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