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In brief: I want to know if an HDD with failed SMART can be repaired by any means, and if so, is it still reliable enough.

In details: I have a 4 years old 1TB Western Digital HDD (WD10JPVX-08JC3T6) with no previous problems.

disk /dev/sda: 931.5 gib, 1000204886016 bytes, 1953525168 sectors
units: sectors of 1 * 512 = 512 bytes
sector size (logical/physical): 512 bytes / 4096 bytes
i/o size (minimum/optimal): 4096 bytes / 4096 bytes
disklabel type: gpt
disk identifier: c700a041-8c28-42e8-9adb-24a5f86b961a

device          start        end    sectors   size type
/dev/sda1        2048    1050623    1048576   512m efi system
/dev/sda2     1050624 1936945151 1935894528 923.1g linux filesystem
/dev/sda3  1936945152 1953523711   16578560   7.9g linux swap

All of a sudden (worth mentioning: probably in a high humidity condition) I found that my Debian root partition sda2 is read-only. I ran a samrtctl long test, which was completed with read failure, Current_Pending_Sector was 109 and Reallocated_Event_Count was 0.

smartctl 6.6 2016-05-31 r4324 [x86_64-linux-4.15.0-29-generic] (local build)
Copyright (C) 2002-16, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF INFORMATION SECTION ===
Model Family:     Western Digital Blue Mobile
Device Model:     WDC WD10JPVX-08JC3T6
Serial Number:    WD-WX31A27AYEN4
LU WWN Device Id: 5 0014ee 65cbcd3de
Firmware Version: 08.01A08
User Capacity:    1,000,204,886,016 bytes [1.00 TB]
Sector Sizes:     512 bytes logical, 4096 bytes physical
Rotation Rate:    5400 rpm
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, 6.0 Gb/s (current: 6.0 Gb/s)
Local Time is:    Wed Sep 23 14:49:11 2020 UTC
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:        (18000) 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:    ( 202) minutes.
Conveyance self-test routine
recommended polling time:    (   5) minutes.
SCT capabilities:          (0x7035) 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       -       677
  3 Spin_Up_Time            0x0027   189   179   021    Pre-fail  Always       -       1533
  4 Start_Stop_Count        0x0032   091   091   000    Old_age   Always       -       9943
  5 Reallocated_Sector_Ct   0x0033   200   200   140    Pre-fail  Always       -       0
  7 Seek_Error_Rate         0x002f   200   200   051    Pre-fail  Always       -       0
  9 Power_On_Hours          0x0032   082   082   000    Old_age   Always       -       13700
 10 Spin_Retry_Count        0x0032   100   100   000    Old_age   Always       -       0
 11 Calibration_Retry_Count 0x0032   100   100   000    Old_age   Always       -       0
 12 Power_Cycle_Count       0x0032   099   099   000    Old_age   Always       -       1834
192 Power-Off_Retract_Count 0x0032   200   200   000    Old_age   Always       -       119
193 Load_Cycle_Count        0x0032   139   139   000    Old_age   Always       -       185919
194 Temperature_Celsius     0x0022   113   089   000    Old_age   Always       -       34
196 Reallocated_Event_Count 0x0032   200   200   000    Old_age   Always       -       0
197 Current_Pending_Sector  0x0032   200   200   000    Old_age   Always       -       109
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
240 Head_Flying_Hours       0x0032   084   084   000    Old_age   Always       -       12291


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: read failure       40%     13684         1385167592


2  Short offline       Completed without error       00%     13682         -


3  Extended offline    Completed: read failure       30%     13678         1385167592


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.

So I unmounted sda2, took the back up and ran a e2fsck -fccky on it (which runs badblocks internally), which complained for IO errors in a continuous group of blocks, while also repairing the filesystem. Then, hoping this had helped anything, I ran another smartctl long test, only to find out that Current_Pending_Sector is increased to 786 and the LBA_of_first_error is much smaller now.

Following many people who had considered a drive with a failed SMART as a dead drive (like many answers here), I was ready to let my HDD go, till I found some place (with no affiliation to WD) who claimed they can 'repair' my HDD, with a tool called PC-3000. They did their job and said that the drive is healthy now, but I couldn't confirm: I ran another smartctl long test and it was a read failure again, but all my previous SMART reports were gone and this time, both Current_Pending_Sector and Reallocated_Event_Count were 0. I also ran another badblocks on the drive only to find the same IO errors. I even dded the reported blocks to confirm that they can't be read. Their technician ignorantly insisted that I should just install Windows on the drive to see if it's working. Certain that the Windows installer won't even be able to make an NTFS filesystem there, I just made a small 2M partition around the error spot (which was about 744 blocks of 512B) and ran a complete mkfs.ntfs (with zeroing) there. To my surprise, the filesystem was created successfully. I mounted it and was able to read/write the whole partition. Once again I dded those bad blocks, and successfully read them this time. And at last, I ran another smartctl long test, which also passed successfully. (Although still with a high Raw_Read_Error_Rate.) Here you can see the result of the tests #2 and #1, which were done before and after the mkfs.ntfs, respectively.

smartctl 6.6 2016-05-31 r4324 [x86_64-linux-4.15.0-29-generic] (local build)
Copyright (C) 2002-16, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF INFORMATION SECTION ===
Model Family:     Western Digital Blue Mobile
Device Model:     WDC WD10JPVX-08JC3T6
Serial Number:    WD-WX31A27AYEN4
LU WWN Device Id: 5 0014ee 65cbcd3de
Firmware Version: 08.01A08
User Capacity:    1,000,204,886,016 bytes [1.00 TB]
Sector Sizes:     512 bytes logical, 4096 bytes physical
Rotation Rate:    5400 rpm
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, 6.0 Gb/s (current: 6.0 Gb/s)
Local Time is:    Thu Oct  8 05:54:51 2020 UTC
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:        (18000) 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:    ( 202) minutes.
Conveyance self-test routine
recommended polling time:    (   5) minutes.
SCT capabilities:          (0x7035) 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       -       410
  3 Spin_Up_Time            0x0027   189   184   021    Pre-fail  Always       -       1550
  4 Start_Stop_Count        0x0032   100   100   000    Old_age   Always       -       34
  5 Reallocated_Sector_Ct   0x0033   200   200   140    Pre-fail  Always       -       0
  7 Seek_Error_Rate         0x002f   200   200   051    Pre-fail  Always       -       0
  9 Power_On_Hours          0x0032   100   100   000    Old_age   Always       -       44
 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       -       14
192 Power-Off_Retract_Count 0x0032   200   200   000    Old_age   Always       -       9
193 Load_Cycle_Count        0x0032   200   200   000    Old_age   Always       -       33
194 Temperature_Celsius     0x0022   108   095   000    Old_age   Always       -       39
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       -       2
200 Multi_Zone_Error_Rate   0x0008   200   200   000    Old_age   Offline      -       0
240 Head_Flying_Hours       0x0032   100   100   000    Old_age   Always       -       34


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%        44         -


2  Extended offline    Completed: read failure       40%        29         1345188144


3  Short offline       Completed without error       00%        27         -


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.

Then I also ran another badblocks on the whole drive, which found no errors.

Update: I just restored my backup image‒which means writing on every single virtually available block on the disk‒and ran another successful smartctl -t long.

Now to summarize the above:

  1. The drive had a failed SMART, and blocks with IO errors, which were apparantly increasing,
  2. something unknown to me was done to the drive, using this PC-3000,
  3. the drive was in the same state, SMART still failed but it's previous data was gone,
  4. I mkfs.ntfsed the error spot, and
  5. suddenly errors were gone and SMART test passed successfully.
  • Notice that I didn't explicitly write on the error spot, although I guess badblocks does this anyway.

My questions:

  1. Is there any explanations for what exactly happened? Was it really damaged and was it really fixed? How then? My simple guesses:

    A. I just misinterpretted the SMART test as failing. It was good from the beginning.

    B. The PC-3000 had done it's job, but the drive was just waiting for a write on the error spot to do whatever it did to repair them. (like remapping the blocks)

    • I don't think mkfs.ntfs did anything except just writing zeroes (or probably its filesystem stuff) on the error spot, right?

  2. Is my drive reliable now? Can I use it with no more concerns? And if so, does that mean a drive with failed SMART can be repaired?

  3. What might this PC-3000 possibly do? Is it really a 'hardware fix' for physically damaged drive?

Beleg
  • 123

1 Answers1

2

Some background: Modern HDDs have some spare sectors to replace bad ones and each sector has extra bits to detect errors and recover from simpler ones. When a HDD find a read error it don't relocate immediately to allow you the user to try to recover missing data. But when a write is done on the failed sector it writes over corrupted data, check if data was correctly written and if there are checksum errors, relocates the failed sector. It doesn't always relocate because the problem can be transient (for example, data could be corrupted due to a power outage during a write).

And now the answer for your questions:

  1. A failed smart test means there's a sector with unrecoverable (using internal recovery algorithms) checksum errors in your disk, not necessarily that the entire disk is dying. There are organizations that replace disks at this point to be sure, but I have seen a questionable batch of HDDs relocating some sectors in their first days and them stabilizing and working correctly for several years.

I don't know what this PC-3000 card do, but as you where still getting read errors, it seems that it does not triggered relocation of all bad sectors.

When you run mkfs.ntfs and asked to zero the entire partition and all your test targeting the troubled area passed after that, it seems that it triggered relocation of the bad sectors. Probably Reallocated_Event_Count isn't zero anymore.

  1. Probably not. It seems that the bad sector where repaired, but as you still having high Raw_Read_Error_Rate, there are other sectors that eventually will fail and if your Current_Pending_Sector reached 786, not all sectors where remapped or you drive is about to use all spare sectors. It seems your drive is reaching the end of its life. It may hold on for some time, but I wouldn't trust it for important data.

  2. I don't know. As it is a hardware solution and use extra connectors, maybe it can tweak HDD firmware or use debug commands to access raw data and checksum.

Bruno Coutinho
  • 216