最後更新: 2017-11-12

介紹

• HDD (傳統 Harddisk)
• SSD

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傳統 HDD

 

與 HDD 年齡有關

3     Spin_Up_Time [millisecs]

轉速由 0 rpm 到 7200 rpm (fully operational) 所需的平均時間(ms) {這個個程叫 spindle spinup}

此數值與 Harddisk 的碟數有關, 愈多碟啟動得愈慢

4     Start_Stop_Count

spindle 的 On/Off 次數, 它包括了 harddisk 的 sleep（Load_Cycle_Count）及熄著 (Power_Cycle_Count)

9     Power_On_Hours

12   Power_Cycle_Count

192 Power-Off Retract Cycle

non-standard power-ff cycles (Unexpected power loss count) <- Hard Reset

The count of times the magnetic armature was retracted(縮回) automatically as a result of cutting power.

193  Load_Cycle_Count

unload heads often to conserve power

WD Green Disk:

   positioning the heads in a park position (unloading the heads) and turning off unnecessary electronics

    * drive has been validated to 1 million load/unload cycles without issue

240  Head_Flying_Hours

Time a disk head spent in the data zone, rather than in the parking area or on a head ramp.

The Raw value often holds the actual number of hours.

i.e. ST3000DM001

240 Head_Flying_Hours       0x0000   100   253   000    Old_age   Offline      -       18172h+48m+01.534s

241 Total_LBAs_Written

Represents the total size of all LBAs (Logical Block Address) required for all of the write requests sent to the HDD from the OS.

To calculate the total size (in Bytes), multiply the raw value of this attribute by 512B.

(Sector Sizes: 512 bytes logical, 4096 bytes physical) <-- 即使 physical 係 4k, 仍用 512B 去計

dd partation

1073741824 bytes (1.1 GB, 1.0 GiB) copied

前: 44294604149

後: 44296701301

Diff: 2097152

1073741824 / 2097152 = 512 byte

 

有幾殘(Pre-fail):

• id 1         Raw_Read_Error_Rate                     # (Vendor specific raw value.)
• id 5         Reallocated_Sector_Ct [remaps]
• id 7         Seek_Error_Rate                             # (Vendor specific raw value.)
• id 10       Spin Retry Count                             # 幾多次不能直接去全速
• id 187     Reported_Uncorrect
• id 196     Reallocated_Event_Count
• id 197     Current_Pending_Sector
• id 198     Offline_Uncorrectable
• id 200     Multi_Zone_Error_Rate                # The count of errors found when writing a sector.

Reallocated_Sector_Ct(5)

有多小個 Sector re-map 了

Reported_Uncorrect(187)

The count of errors that could not be recovered using hardware ECC

"reads" 時發生

Reallocated_Event_Count (196)

When the hard drive finds a read/write/verification error

This number also affects performance (to seek to the reserved area)

remapped sectors can be manually marked as bad blocks in the file system in order to prevent their use.

Both successful and unsuccessful attempts remap are counted.

Current_Pending_Sector (197)

Unreadable during normal operation.(RW)

Count of "unstable" sectors (waiting to be remapped, because of unrecoverable read errors)

If an unstable sector is subsequently read successfully, the sector is remapped and this value is decreased.

Read errors on a sector will not remap the sector immediately
(since the correct value cannot be read and so the value to remap is not known,
and also it might become readable later);

Instead, the drive firmware remembers that the sector needs to be remapped,
and will remap it the next time it's written.

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However some drives will not immediately remap such sectors when written;
Instead the drive will first attempt to write to the problem sector and
if the write operation is successful then the sector will be marked good
(in this case, the "Reallocation Event Count" (0xC4) will not be increased).

This is a serious shortcoming, for if such a drive contains marginal sectors that consistently fail
only after some time has passed following a successful write operation,
then the drive will never remap these problem sectors.

Offline_Uncorrectable (198)

A harddisk encounters an uncorrectable error during offline testing.

uncorrectable - the error cannot be corrected by the drive's error correction mechanisms(ECC)

Offline testing - the disk's self-checking process that occurs when the disk is not actively being used.

意外 (趺過)

189 High_Fly_Writes

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.

(External shock, vibration, media defect or contamination may cause this.)

191 G-Sense_Error_Rate

indicates the number of errors caused by externally-induced shock or vibration

 

其他

• id11      Calibration_Retry_Count
• id194    Temperature_Celsius
• id199    UDMA_CRC_Error_Count

 

特定 Harddisk 才有

End-to-End_Error (184)

This attribute is a part of Hewlett-Packard's SMART IV technology

It contains a count of parity errors which occur in the data path to the media via the drive's cache RAM

 

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Vendor-specific raw value (1, 7, 195)

 

ID

1       # Raw_Read_Error_Rate    (Vendor-specific raw value)

7       # Seek_Error_Rate

195   # Hardware_ECC_Recovered (Vendor-specific raw value)

Check by cmd

smartctl -A /dev/sda | grep -e Raw_Read_Error_Rate -e Hardware_ECC_Recovered -e Seek_Error_Rate

  1 Raw_Read_Error_Rate     0x000f   119   099   006    Pre-fail  Always       -       207302664
  7 Seek_Error_Rate         0x000f   084   060   030    Pre-fail  Always       -       4608610004
195 Hardware_ECC_Recovered  0x001a   023   007   000    Old_age   Always       -       207302664

 

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SSD

 

log

177 Wear_Leveling_Count     0x0013   099   099   000    Pre-fail  Always       -       6
179 Used_Rsvd_Blk_Cnt_Tot   0x0013   100   100   010    Pre-fail  Always       -       0
181 Program_Fail_Cnt_Total  0x0032   100   100   010    Old_age   Always       -       0
182 Erase_Fail_Count_Total  0x0032   100   100   010    Old_age   Always       -       0
183 Runtime_Bad_Block       0x0013   100   100   010    Pre-fail  Always       -       0
187 Reported_Uncorrect      0x0032   100   100   000    Old_age   Always       -       0
190 Airflow_Temperature_Cel 0x0032   065   058   000    Old_age   Always       -       35
195 Hardware_ECC_Recovered  0x001a   200   200   000    Old_age   Always       -       0
199 UDMA_CRC_Error_Count    0x003e   100   100   000    Old_age   Always       -       0
235 POR Recovery Count       0x0012   099   099   000    Old_age   Always      -       19
241 Total_LBAs_Written      0x0032   099   099   000    Old_age   Always       -       1338616004

177. Wear_Leveling_Count

the number of media program and erase operations (P/E Cycles)
This value is directly related to the lifetime of the SSD.

SLC ~ 100,000
MLC ~ 3,000
TLC ~ 1,000

179 Used Reserved Block Count (total)

This attribute represents the number of reserved blocks that have been used as a result of a read, program or erase failure.
This value is related to attribute 5 (Reallocated Sector Count) and will vary based on SSD density.

181 Program Fail Count (total)

This attribute represents a total count of the number of failed program requests (failed writes).

182 Erase Fail Count (total)

This attribute represents a total count of the number of failed erase requests.

183 Runtime Bad Count (total)

This summary value represents the total count of all read/program/erase failures.
sum of the
Program Fail count (attribute 181),
the Program Erase Fail count (attribute 182),
Read Fail count

235. POR Recovery Count

A count of the number of sudden power off cases.

If there is a sudden power off, the firmware must recover all of the mapping and user data during the next power on.

This is a count of the number of times this has happened.

241. Total_LBAs_Written

The total number of 512-byte sectors written during the entire lifetime of the device.