Questionable reliability of HDD SMART-tests

Having some doubts on the reliability of SMART-testing since I have now had multiple drives that would report a smart failure and have tests pass after rerunning them.

Has anyone else had similar experiences?

Here is a sample from a 6TB drive

smartctl 7.2 2020-12-30 r5155 [x86_64-linux-5.15.107+truenas] (local build)
Copyright (C) 2002-20, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF INFORMATION SECTION ===
Model Family:     Western Digital Red
Device Model:     WDC WD60EFRX-68MYMN1
Serial Number:    WD-WX81D65ASU5T
LU WWN Device Id: 5 0014ee 2b7349cf1
Firmware Version: 82.00A82
User Capacity:    6,001,175,126,016 bytes [6.00 TB]
Sector Sizes:     512 bytes logical, 4096 bytes physical
Rotation Rate:    5700 rpm
Device is:        In smartctl database [for details use: -P show]
ATA Version is:   ACS-2, ACS-3 T13/2161-D revision 3b
SATA Version is:  SATA 3.1, 6.0 Gb/s (current: 6.0 Gb/s)
Local Time is:    Tue Sep  5 10:59:04 2023 EEST
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:      (   0) The previous self-test routine completed
                                        without error or no self-test has ever
                                        been run.
Total time to complete Offline
data collection:                ( 3824) 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:        ( 692) minutes.
Conveyance self-test routine
recommended polling time:        (   5) minutes.
SCT capabilities:              (0x303d) SCT Status supported.
                                        SCT Error Recovery Control 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   210   193   021    Pre-fail  Always       -       8483
  4 Start_Stop_Count        0x0032   100   100   000    Old_age   Always       -       19
  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   016   016   000    Old_age   Always       -       61545
 10 Spin_Retry_Count        0x0032   100   253   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       -       18
192 Power-Off_Retract_Count 0x0032   200   200   000    Old_age   Always       -       9
193 Load_Cycle_Count        0x0032   174   174   000    Old_age   Always       -       79448
194 Temperature_Celsius     0x0022   121   106   000    Old_age   Always       -       31
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  Extended offline    Completed without error       00%     61542         -
# 2  Extended offline    Completed: read failure       80%     61440         1542477488
# 3  Extended offline    Completed without error       00%     60709         -
# 4  Extended offline    Completed without error       00%     59965         -
# 5  Short offline       Completed without error       00%     55831         -
# 6  Short offline       Completed without error       00%     55663         -
# 7  Extended offline    Completed without error       00%     55500         -
# 8  Short offline       Completed without error       00%     55327         -
# 9  Short offline       Completed without error       00%     55159         -
#10  Short offline       Completed without error       00%     54992         -
#11  Short offline       Completed without error       00%     54824         -
#12  Extended offline    Completed without error       00%     54780         -
#13  Short offline       Completed without error       00%     54658         -
#14  Short offline       Completed without error       00%     54492         -
#15  Short offline       Completed without error       00%     54324         -
#16  Short offline       Completed without error       00%     54156         -
#17  Extended offline    Completed without error       00%     54040         -
#18  Short offline       Completed without error       00%     53988         -
#19  Short offline       Completed without error       00%     53820         -
#20  Short offline       Completed without error       00%     53652         -
#21  Short offline       Completed without error       00%     53485         -
1 of 1 failed self-tests are outdated by newer successful extended offline self-test # 1

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.

That Multi_Zone_Error_Rate of 1 probably correlates to the failed test. If Multi_Zone_Error_Rate continues to climb, definitely time to replace the drive.

If it was still under warranty, one failed self-test would be enough of a reason to RMA.

Drives are “self-healing” in that regard that they can map areas as bad and continue. This normal behaviour however excessive amounts is usually a sign of a dying drive.

1 Like

It’s also possible, though the mechanical nature of a mechanical drive, for a mechanical error to occur due to external factors. An error doesn’t necessarily mean something is failed, just that it didn’t behave correctly in that moment.
Just down to law of averages and the impossibility of making something absolutely perfect, drives do have an expected read error rate that is greater than 0 under perfect conditions.

It looks like you have a bad sector though, which has been blacklisted to prevent data loss.

That said, from what I’ve read in the past, smart tests absolutely can lie. It’s not abnormal for a drive to actually have errors that aren’t reported because the drive can correct it’s self fully and completely mask the problem. In this case, however, you won’t even be presented with an error. The drive will reread the area, find the correct data this time, and present it as though it never erred.

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Well at 61545 hours we might be a bit out of warranty :slight_smile:

TBH It behooves me to say that I’m impressed. That’s pretty good for Western Digital mechanical hard drives. What was the date on that drive again? These days you can purchase a WD hard drive and it will start generating SMART errors in a matter of days. (Sorry fans, but this has happened to me more times than I care to count and that’s why I stopped buying them.)

I have one Western Digital 3TB (Green) drive that absolutely refuses to die on me. I am convinced that it is there to defy me. It won’t click, doesn’t chatter, and I often forget that I even have it. I use it as a utility drive in an external enclosure and that’s where it stays. I also have a RAID 10 array of very, very old Velociraptors that have never given me a problem, but this is from back in the day when Western Digital was sincerely dedicated to quality. I don’t think there are so much anymore.

Given my past experience as a PC repair guy the name that came up the most for replacing mechanical hard drives was Western Digital. The straw that broke the proverbial camel’s back was when I purchased a brand new Caviar Black 1TB drive and it started clicking within two days of receiving it. When I called up Western Digital for a return the customer support guy said, “Okay, but just this once.” Suffice it to say I agreed with him. I’ve not purchased a brand new Western Digital mechanical drive since. To add insult to injury the replacement drive also failed. So much for the warranty.

I know of others who have had a different experience with Western Digital mechanical drives and if they’re happy with them that’s the main thing. As for me (and several others I’ve shared with) I’m done buying spinners from Western Digital. They just don’t make 'em like they used to.