smartctl报告整体健康测试通过，但测试失败？

Question

当两个测试失败时，为什么会显示SMART overall-health self-assessment test result: PASSED？

sudo smartctl -a /dev/sdc 
smartctl 6.6 2018-12-05 r4851 [x86_64-linux-4.14.98] (local build)
Copyright (C) 2002-17, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF INFORMATION SECTION ===
Model Family:     Western Digital AV-GP (AF)
Device Model:     WDC WD20EURS-63SPKY0
Serial Number:    WD-WMC1T2763021
LU WWN Device Id: 5 0014ee 6addb4b7c
Firmware Version: 80.00A80
User Capacity:    2,000,398,934,016 bytes [2.00 TB]
Sector Sizes:     512 bytes logical, 4096 bytes physical
Device is:        In smartctl database [for details use: -P show]
ATA Version is:   ACS-2 (minor revision not indicated)
SATA Version is:  SATA 3.0, 3.0 Gb/s (current: 3.0 Gb/s)
Local Time is:    Sun Feb 24 13:43:30 2019 GMT
SMART support is: Available - device has SMART capability.
SMART support is: Enabled

=== START OF READ SMART DATA SECTION ===
SMART overall-health self-assessment test result: PASSED

General SMART Values:
Offline data collection status:  (0x00) Offline data collection activity
                    was never started.
                    Auto Offline Data Collection: Disabled.
Self-test execution status:      ( 117) The previous self-test completed having
                    the read element of the test failed.
Total time to complete Offline 
data collection:        (27240) seconds.
Offline data collection
capabilities:            (0x7b) SMART execute Offline immediate.
                    Auto Offline data collection on/off support.
                    Suspend Offline collection upon new
                    command.
                    Offline surface scan supported.
                    Self-test supported.
                    Conveyance Self-test supported.
                    Selective Self-test supported.
SMART capabilities:            (0x0003) Saves SMART data before entering
                    power-saving mode.
                    Supports SMART auto save timer.
Error logging capability:        (0x01) Error logging supported.
                    General Purpose Logging supported.
Short self-test routine 
recommended polling time:    (   2) minutes.
Extended self-test routine
recommended polling time:    ( 275) minutes.
Conveyance self-test routine
recommended polling time:    (   5) minutes.
SCT capabilities:          (0x70b5) SCT Status supported.
                    SCT Feature Control supported.
                    SCT Data Table supported.

SMART Attributes Data Structure revision number: 16
Vendor Specific SMART Attributes with Thresholds:
ID# ATTRIBUTE_NAME          FLAG     VALUE WORST THRESH TYPE      UPDATED  WHEN_FAILED RAW_VALUE
  1 Raw_Read_Error_Rate     0x002f   200   200   051    Pre-fail  Always       -       0
  3 Spin_Up_Time            0x0027   180   179   021    Pre-fail  Always       -       5991
  4 Start_Stop_Count        0x0032   100   100   000    Old_age   Always       -       113
  5 Reallocated_Sector_Ct   0x0033   200   200   140    Pre-fail  Always       -       0
  7 Seek_Error_Rate         0x002e   200   200   000    Old_age   Always       -       0
  9 Power_On_Hours          0x0032   092   092   000    Old_age   Always       -       6354
 10 Spin_Retry_Count        0x0032   100   100   000    Old_age   Always       -       0
 11 Calibration_Retry_Count 0x0032   100   253   000    Old_age   Always       -       0
 12 Power_Cycle_Count       0x0032   100   100   000    Old_age   Always       -       56
192 Power-Off_Retract_Count 0x0032   200   200   000    Old_age   Always       -       46
193 Load_Cycle_Count        0x0032   200   200   000    Old_age   Always       -       66
194 Temperature_Celsius     0x0022   122   114   000    Old_age   Always       -       28
196 Reallocated_Event_Count 0x0032   200   200   000    Old_age   Always       -       0
197 Current_Pending_Sector  0x0032   200   200   000    Old_age   Always       -       0
198 Offline_Uncorrectable   0x0030   100   253   000    Old_age   Offline      -       0
199 UDMA_CRC_Error_Count    0x0032   200   200   000    Old_age   Always       -       0
200 Multi_Zone_Error_Rate   0x0008   200   200   000    Old_age   Offline      -       1

SMART Error Log Version: 1
No Errors Logged

SMART Self-test log structure revision number 1
Num  Test_Description    Status                  Remaining  LifeTime(hours)  LBA_of_first_error
# 1  Short offline       Completed: read failure       50%      6354         4377408
# 2  Extended offline    Completed: read failure       90%      6354         4377408

SMART Selective self-test log data structure revision number 1
 SPAN  MIN_LBA  MAX_LBA  CURRENT_TEST_STATUS
    1        0        0  Not_testing
    2        0        0  Not_testing
    3        0        0  Not_testing
    4        0        0  Not_testing
    5        0        0  Not_testing
Selective self-test flags (0x0):
  After scanning selected spans, do NOT read-scan remainder of disk.
If Selective self-test is pending on power-up, resume after 0 minute delay.

Answer 1

因为您的智能属性都处于良好的状态，并且存在No Errors Logged。

请阅读：ATA驱动器正在失败自我测试，但智能健康状况“通过”。到底怎么回事？

如果驱动器失败了自我测试，但仍然“通过”智能健康状态，这通常意味着磁盘上有一个损坏的(uncorrectable=UNC)扇区。这意味着存储在该扇区的ECC数据与存储在该扇区的用户数据不一致，试图读取该扇区的尝试因UNC错误而失败。这可能是一次短暂的影响:当磁盘写入扇区时突然停电，损坏ECC代码或数据，但是扇区可以正确地存储新数据。或者是永久性的影响:磁性介质被一点灰尘破坏了，而且这个部门无法正确地存储新的数据。如果磁盘能够一次性读取数据扇区，并且损坏是永久性的，而不是暂时的，那么磁盘固件将将该扇区标记为“坏”，并分配一个备用扇区来替换它。但是，如果磁盘一次都不能读取扇区，那么它就不会重新分配扇区，希望在将来的某个时候能够读取该扇区的数据。写入不可读(损坏)扇区将修复此问题。如果损坏是暂时的，那么新的一致数据将被写入该部门。如果是永久的，那么写入将强制扇区重新分配。有关如何强制该扇区重新分配的说明，请参见坏块操作 (仅限于Linux)。由于固件没有发现其他故障迹象，如伺服故障，磁盘仍然保持正常状态。这样的磁盘通常可以通过使用磁盘制造者的“磁盘评估和修复”实用程序来修复。小心:这可能会迫使重新分配丢失的扇区，从而损坏或破坏磁盘上的任何文件系统。请参阅坏块操作以获得通用的Linux指令。

您可以尝试使用dd或某种“修复实用程序”修复不可读扇区。先备份你的硬盘！

Answer 2

使用smartctl，没有简单的命令告诉您一切都好.smartctl -H是一个虚假的朋友，不值得信任。你必须看完整的输出。

SMART overall-health self-assessment test result: PASSED

虽然它说通过了，但它并不意味着什么，所以只要忽略它，并更换失败的驱动器无论如何。

Offline data collection status: 
    (0x00) Offline data collection activity was never started.
           Auto Offline Data Collection: Disabled.

在sidenote上，考虑启用Auto Offline Data Collection，并设置smartd定期运行自我测试并发送电子邮件通知。

每6354个小时进行一次自我测试太不可靠了，如果没有定期的测试，硬盘驱动器的错误就不会被发现，直到做任何事情都为时已晚。