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Currently unreadable (pending) sectors

Joined
Feb 15, 2020
Messages
2
Yet another "Currently unreadable (pending) sectors", my apologies in advance but since this is my first time going through this process I want to double check my troubleshooting steps and conclusions are solid or not. I've gone through multiple posts and articles already, I'll post below what I found and let me know if I'm missing something please.

Sorry, some of the info below may be useless for you, but just to be sure I'm thorough on what I see and checked.

First problems of error, I got a FreeNAS email with "Device: /dev/ada2, 1 Currently unreadable (pending) sectors.". On FreeNAS UI I see:

pools.png


disks.png


With zpool status I get:

Code:
% zpool status
  pool: freenas-boot
 state: ONLINE
  scan: scrub repaired 0 in 0 days 00:01:10 with 0 errors on Thu Feb 13 03:46:10 2020
config:

    NAME        STATE     READ WRITE CKSUM
    freenas-boot  ONLINE       0     0     0
      ada0p2    ONLINE       0     0     0

errors: No known data errors

  pool: storage
 state: ONLINE
  scan: scrub repaired 0 in 0 days 15:56:09 with 0 errors on Sun Feb  2 17:26:43 2020
config:

    NAME        STATE     READ WRITE CKSUM
    storage     ONLINE       0     0     0
      ada1p1    ONLINE       0     0     0

errors: No known data errors


With zpool import I get:

Code:
   pool: newstorage
     id: 3896255639125905409
  state: ONLINE
 action: The pool can be imported using its name or numeric identifier.
 config:

    newstorage                                      ONLINE
      mirror-0                                      ONLINE
        gptid/8b98e792-1cd7-11e9-8fc5-10bf487fdc2b  ONLINE
        gptid/8c9b5767-1cd7-11e9-8fc5-10bf487fdc2b  ONLINE


This matches UI, there is no pool for newstorage. I can't import this newstorage though if I run zpool import newstorage I get:

Code:
cannot import 'newstorage': one or more devices is currently unavailable


Now on to smartctl checks.

smartctl -a /dev/ada2 results:

Code:
smartctl 6.6 2017-11-05 r4594 [FreeBSD 11.2-STABLE amd64] (local build)
Copyright (C) 2002-17, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF INFORMATION SECTION ===
Model Family:     Western Digital Red
Device Model:     WDC WD40EFRX-68N32N0
Serial Number:    WD-WCC7K1AKUS29
LU WWN Device Id: 5 0014ee 2101135aa
Firmware Version: 82.00A82
User Capacity:    4,000,787,030,016 bytes [4.00 TB]
Sector Sizes:     512 bytes logical, 4096 bytes physical
Rotation Rate:    5400 rpm
Form Factor:      3.5 inches
Device is:        In smartctl database [for details use: -P show]
ATA Version is:   ACS-3 T13/2161-D revision 5
SATA Version is:  SATA 3.1, 6.0 Gb/s (current: 3.0 Gb/s)
Local Time is:    Sat Feb 15 12:10:47 2020 CET
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:         (44520) 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:      ( 472) 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   195   189   051    Pre-fail  Always       -       245
  3 Spin_Up_Time            0x0027   241   165   021    Pre-fail  Always       -       2916
  4 Start_Stop_Count        0x0032   100   100   000    Old_age   Always       -       69
  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   088   088   000    Old_age   Always       -       9281
 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       -       69
192 Power-Off_Retract_Count 0x0032   200   200   000    Old_age   Always       -       65
193 Load_Cycle_Count        0x0032   200   200   000    Old_age   Always       -       2526
194 Temperature_Celsius     0x0022   113   107   000    Old_age   Always       -       37
196 Reallocated_Event_Count 0x0032   200   200   000    Old_age   Always       -       0
197 Current_Pending_Sector  0x0032   200   200   000    Old_age   Always       -       1
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   100   253   000    Old_age   Offline      -       0

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       90%      9174         3807998688
# 2  Extended offline    Completed: read failure       90%      9170         3807998688
# 3  Short offline       Completed: read failure       90%      9150         3807998688
# 4  Extended offline    Completed: read failure       90%      9147         3807998688
# 5  Extended offline    Completed: read failure       90%      9142         3807998688

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.


According to what I read and understood from the troubleshooting article, the concerning part for me is Current_Pending_Sector being > 0. So, I did the Drive Data Refreshing step, didn't help. I didn't do any other step here I didn't understand well the other steps and I didn't want to make the situation possibly worse. I also don't understand the part "read failure" on the results listed above. I know that is a failure but not sure if just a consequence of the numbers above or if it is an indication of another problem, ...

Just for completeness sake, smartctl -a /dev/ada1 results:

Code:
smartctl 6.6 2017-11-05 r4594 [FreeBSD 11.2-STABLE amd64] (local build)
Copyright (C) 2002-17, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF INFORMATION SECTION ===
Model Family:     Western Digital Red
Device Model:     WDC WD40EFRX-68WT0N0
Serial Number:    WD-WCC4E0694999
LU WWN Device Id: 5 0014ee 25ef1ab53
Firmware Version: 80.00A80
User Capacity:    4,000,787,030,016 bytes [4.00 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:    Sat Feb 15 12:11:32 2020 CET
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:         (54300) 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:      ( 543) minutes.
Conveyance self-test routine
recommended polling time:      (   5) minutes.
SCT capabilities:            (0x703d)    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       -       10
  3 Spin_Up_Time            0x0027   208   174   021    Pre-fail  Always       -       6566
  4 Start_Stop_Count        0x0032   100   100   000    Old_age   Always       -       192
  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   033   033   000    Old_age   Always       -       49593
 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   100   100   000    Old_age   Always       -       191
192 Power-Off_Retract_Count 0x0032   200   200   000    Old_age   Always       -       139
193 Load_Cycle_Count        0x0032   197   197   000    Old_age   Always       -       9497
194 Temperature_Celsius     0x0022   113   106   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       -       0
200 Multi_Zone_Error_Rate   0x0008   200   200   000    Old_age   Offline      -       0

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 without error       00%     49485         -
# 2  Short offline       Completed without error       00%     49461         -
# 3  Short offline       Completed without error       00%     49450         -
# 4  Extended offline    Completed without error       00%     49414         -
# 5  Short offline       Completed without error       00%     49294         -
# 6  Short offline       Completed without error       00%     49067         -
# 7  Extended offline    Completed without error       00%     49054         -
# 8  Short offline       Completed without error       00%     48947         -
# 9  Short offline       Completed without error       00%     48707         -
#10  Extended offline    Completed without error       00%     48670         -
#11  Short offline       Completed without error       00%     48540         -
#12  Short offline       Completed without error       00%     48324         -
#13  Extended offline    Completed without error       00%     48316         -
#14  Short offline       Completed without error       00%     48209         -
#15  Short offline       Completed without error       00%     47969         -
#16  Extended offline    Completed without error       00%     47935         -
#17  Short offline       Completed without error       00%     47802         -
#18  Short offline       Completed without error       00%     47610         -
#19  Extended offline    Completed without error       00%     47597         -
#20  Short offline       Completed without error       00%     47490         -
#21  Short offline       Completed without error       00%     47250         -

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.


No errors on the drive.

So, my conclusions here and questions are,
  1. Yes, there is a problem with ada2. My doubt here, from my understanding the problem of Current_Pending_Sector being 1 shouldn't be big enough to make the drive completely offline... What am I missing? Is there anything I can do before going to replacing hardware (cable and/or disk)?
  2. If I replace the drive, what shall I expect? The pool is offline, I can't import it now,... When I replace the drive will I be able to import the pool? Will it resilver by itself and everything will be magical again? From reading the manual on replacing drives, I'm supposed to put the pool offline, but it seems it is already offline. I can't see now any option to 'replace', but will I see it when I've put in the new drive?
Thanks a lot in advance!
 

danb35

FreeNAS Wizard
Joined
Aug 16, 2011
Messages
10,909
the concerning part for me is Current_Pending_Sector being > 0
That is a concern, though having it at 1 isn't necessarily cause for immediate replacement. The Raw Read Error Rate is also high, which is also of concern (and it's a noted issue on ada1 as well). What's of greater concern is that the disk has failed every SMART self-test it's done, which absolutely justifies replacing the disk. But, as you say, that shouldn't result in inability to import the pool, especially since it's a mirror.

What happens if you remove ada2 from the system? Can you import newstorage then?
 
Joined
Feb 15, 2020
Messages
2
Thanks Dan for the reply. The FreeNAS box is at a place not really easy for me to access (besides it being 'hidden' I have some mobility impairments as well). So, I'm leaving the physical work as last resort.

Sorry to ask, but just so I'm sure of the next steps:
If I unplug ada2 and if I'm able to import newstorage, I wouldn't be able to do anything with ada2 per se to recover it, correct?
If I unplug ada2 and if I'm not able to import newstorage, would it mean the problem is possibly worse? Or to find out I'd still have to replace ada2?

Is there anything I can / should try to recover ada2 besides physically replacing it?
 
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