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zpool CKSUM errors while resilvering after replacing a drive

Western Digital Drives - The Preferred Drives of FreeNAS and TrueNAS CORE

mbonato

Newbie
Joined
Aug 22, 2019
Messages
3
Hi! This is my first post to the forum, so I apologise in advance if I miss out on any of the rules. However, I will try me best ;-)

We have a FreeNAS mini box (2016) that worked quite fine until a few days. One of the drives started to show errors in SMART and we decided to replace the drive with a new one. I followed the instructions from the official documentation (https://www.ixsystems.com/documentation/freenas/11.2/storage.html#replacing-a-failed-disk) to replace the failing disk. After I've replaced the disk in the zpool resilvering started as expected. However, after a few hours resilvering stopped and zpool status showed thousands of CKSUM errors and it stated "too many errors" for all the other drives in the pool:
Code:
  pool: nas
 state: DEGRADED
status: One or more devices has experienced an error resulting in data
    corruption.  Applications may be affected.
action: Restore the file in question if possible.  Otherwise restore the
    entire pool from backup.
   see: http://illumos.org/msg/ZFS-8000-8A
  scan: resilvered 2.41T in 0 days 19:46:37 with 3064 errors on Wed Aug 21 08:49:14 2019
config:

    NAME                                              STATE     READ WRITE CKSUM
    nas                                               DEGRADED     0     0 10.6K
      raidz1-0                                        DEGRADED     0     0 37.0K
        gptid/095eaba3-3c9b-11e6-a8b9-d05099c0ff1f    DEGRADED     0     0     0  too many errors
        replacing-1                                   OFFLINE      0     0     0
          130027861328944270                          OFFLINE      0     0     0  was /dev/gptid/0a27642e-3c9b-11e6-a8b9-d05099c0ff1f
          gptid/02fc3662-c33a-11e9-abfd-d05099c38b3b  ONLINE       0     0     0
        gptid/0b0c6d57-3c9b-11e6-a8b9-d05099c0ff1f    DEGRADED     0     0   212  too many errors
        gptid/0be771f2-3c9b-11e6-a8b9-d05099c0ff1f    DEGRADED     0     0     0  too many errors


I spend some hours searching online and reading documentation, however I still don't understand if this is actually a hardware issue or "only" the pool (data) being corrupt beyond repair.

I'm still able to access most of the data and there are replication tasks for all relevant datasets. Also periodic SMART tests are in place and SMART does not report any issues with the other disks.

In the posts referring to similar issues I've found so far, it has been suggested that this might be caused by general hardware issues like inappropriate hardware, failing RAM etc. Since we use a FreeNAS mini box, I assume appropriate hardware ;-). Also RAM should be ECC according to the specs. Therefore, I would expect to notice if RAM is failing!? (System has not crashed and BMC event log does not show any errors.)

I've tried to reboot the FreeNas and resilvering started again automatically. However, with the same results - showing "too many errors" after a while.

So my questions are:
  • What could be the reason for the CKSUM errors? Are all the other drives failing as well - although they don't show any READ or WRITE errors and SMART does not indicate any drive issues?
  • What is the best way to proceed? Can I recover from the errors (i accept loosing some data) without the need to rebuild the entire pool configuration? Do I need to replace the other harddisks as well?

Thank you very much in advance,
Martin


Code:
# smartctl -a /dev/ada1
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-WCC4E5SHSYVV
LU WWN Device Id: 5 0014ee 261ffe05b
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
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: 3.0 Gb/s)
Local Time is:    Thu Aug 22 13:48:18 2019 CEST
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:         (51540) 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:      ( 515) 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       -       0
  3 Spin_Up_Time            0x0027   181   179   021    Pre-fail  Always       -       7941
  4 Start_Stop_Count        0x0032   100   100   000    Old_age   Always       -       43
  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   062   062   000    Old_age   Always       -       28224
 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       -       43
192 Power-Off_Retract_Count 0x0032   200   200   000    Old_age   Always       -       20
193 Load_Cycle_Count        0x0032   200   200   000    Old_age   Always       -       1171
194 Temperature_Celsius     0x0022   120   108   000    Old_age   Always       -       32
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   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 without error       00%     28137         -
# 2  Short offline       Completed without error       00%     28136         -
# 3  Short offline       Completed without error       00%     28135         -
# 4  Short offline       Completed without error       00%     28134         -
# 5  Short offline       Completed without error       00%     28133         -
# 6  Short offline       Completed without error       00%     28132         -
# 7  Short offline       Completed without error       00%     28131         -
# 8  Short offline       Completed without error       00%     28130         -
# 9  Short offline       Completed without error       00%     28129         -
#10  Short offline       Completed without error       00%     28128         -
#11  Short offline       Completed without error       00%     28127         -
#12  Short offline       Completed without error       00%     28126         -
#13  Short offline       Completed without error       00%     28125         -
#14  Short offline       Completed without error       00%     28124         -
#15  Short offline       Completed without error       00%     28123         -
#16  Short offline       Completed without error       00%     28123         -
#17  Short offline       Completed without error       00%     28121         -
#18  Short offline       Completed without error       00%     28121         -
#19  Short offline       Completed without error       00%     28120         -
#20  Short offline       Completed without error       00%     28119         -
#21  Short offline       Completed without error       00%     28118         -

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.


Code:
# smartctl -a /dev/ada2
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-WCC7K2JUCUKY
LU WWN Device Id: 5 0014ee 21167d6f2
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:    Thu Aug 22 13:49:01 2019 CEST
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:         (43440) 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:      ( 462) 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   100   253   021    Pre-fail  Always       -       0
  4 Start_Stop_Count        0x0032   100   100   000    Old_age   Always       -       1
  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   100   100   000    Old_age   Always       -       48
 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       -       1
192 Power-Off_Retract_Count 0x0032   200   200   000    Old_age   Always       -       0
193 Load_Cycle_Count        0x0032   200   200   000    Old_age   Always       -       1
194 Temperature_Celsius     0x0022   119   116   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   100   253   000    Old_age   Offline      -       0

SMART Error Log Version: 1
No Errors Logged

SMART Self-test log structure revision number 1
No self-tests have been logged.  [To run self-tests, use: smartctl -t]

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.


Code:
# smartctl -a /dev/ada3
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-WCC4E7RP1H6Y
LU WWN Device Id: 5 0014ee 2b7559aa7
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
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: 3.0 Gb/s)
Local Time is:    Thu Aug 22 13:51:57 2019 CEST
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:         (54240) 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:      ( 542) 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       -       0
  3 Spin_Up_Time            0x0027   253   177   021    Pre-fail  Always       -       4200
  4 Start_Stop_Count        0x0032   100   100   000    Old_age   Always       -       47
  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   062   062   000    Old_age   Always       -       28221
 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       -       47
192 Power-Off_Retract_Count 0x0032   200   200   000    Old_age   Always       -       24
193 Load_Cycle_Count        0x0032   200   200   000    Old_age   Always       -       1161
194 Temperature_Celsius     0x0022   119   108   000    Old_age   Always       -       33
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   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 without error       00%     28117         -
# 2  Short offline       Completed without error       00%     28116         -
# 3  Short offline       Completed without error       00%     28115         -
# 4  Short offline       Completed without error       00%     28113         -
# 5  Short offline       Completed without error       00%     28112         -
# 6  Short offline       Completed without error       00%     27967         -
# 7  Short offline       Completed without error       00%     27966         -
# 8  Short offline       Completed without error       00%     27965         -
# 9  Short offline       Completed without error       00%     27964         -
#10  Short offline       Completed without error       00%     27963         -
#11  Short offline       Completed without error       00%     27962         -
#12  Short offline       Completed without error       00%     27961         -
#13  Short offline       Completed without error       00%     27960         -
#14  Short offline       Completed without error       00%     27959         -
#15  Short offline       Completed without error       00%     27958         -
#16  Short offline       Completed without error       00%     27957         -
#17  Short offline       Completed without error       00%     27956         -
#18  Short offline       Completed without error       00%     27955         -
#19  Short offline       Completed without error       00%     27954         -
#20  Short offline       Completed without error       00%     27953         -
#21  Short offline       Completed without error       00%     27952         -

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.


Code:
# smartctl -a /dev/ada4
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-WCC4E2FFACLN
LU WWN Device Id: 5 0014ee 20ca86e2a
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
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: 3.0 Gb/s)
Local Time is:    Thu Aug 22 13:53:13 2019 CEST
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:         (51540) 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:      ( 515) 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       -       0
  3 Spin_Up_Time            0x0027   185   183   021    Pre-fail  Always       -       7708
  4 Start_Stop_Count        0x0032   100   100   000    Old_age   Always       -       44
  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   062   062   000    Old_age   Always       -       28223
 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       -       44
192 Power-Off_Retract_Count 0x0032   200   200   000    Old_age   Always       -       21
193 Load_Cycle_Count        0x0032   200   200   000    Old_age   Always       -       1215
194 Temperature_Celsius     0x0022   119   108   000    Old_age   Always       -       33
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   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 without error       00%     28137         -
# 2  Short offline       Completed without error       00%     28136         -
# 3  Short offline       Completed without error       00%     28135         -
# 4  Short offline       Completed without error       00%     28134         -
# 5  Short offline       Completed without error       00%     28133         -
# 6  Short offline       Completed without error       00%     28132         -
# 7  Short offline       Completed without error       00%     28131         -
# 8  Short offline       Completed without error       00%     28130         -
# 9  Short offline       Completed without error       00%     28129         -
#10  Short offline       Completed without error       00%     28128         -
#11  Short offline       Completed without error       00%     28127         -
#12  Short offline       Completed without error       00%     28126         -
#13  Short offline       Completed without error       00%     28125         -
#14  Short offline       Completed without error       00%     28124         -
#15  Short offline       Completed without error       00%     28123         -
#16  Short offline       Completed without error       00%     28122         -
#17  Short offline       Completed without error       00%     28121         -
#18  Short offline       Completed without error       00%     28120         -
#19  Short offline       Completed without error       00%     28119         -
#20  Short offline       Completed without error       00%     28118         -
#21  Short offline       Completed without error       00%     28117         -

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.
 

sretalla

Wizened Sage
Joined
Jan 1, 2016
Messages
5,476
The first thing to do would be to run zpool status -v to see what the impacted files are.

I don't see anything concerning on your SMART data, so it could be a cablig issue, perhaps something that got bumped when you were changing out the drive?
 

mbonato

Newbie
Joined
Aug 22, 2019
Messages
3
Thank you for your quick reply!

I've already checked the files affected and tried to follow the ZFS documentation to recover.

In fact most of them where part of a snapshot and I've deleted the snapshot. The rest of the files were also not critical and I deleted them as well. The result was:
Code:
  pool: nas
 state: DEGRADED
status: One or more devices has experienced an error resulting in data
    corruption.  Applications may be affected.
action: Restore the file in question if possible.  Otherwise restore the
    entire pool from backup.
   see: http://illumos.org/msg/ZFS-8000-8A
  scan: scrub in progress since Thu Aug 22 14:10:03 2019
    1.78T scanned at 282M/s, 1.21T issued at 191M/s, 10.3T total
    0 repaired, 11.66% done, 0 days 13:56:20 to go
config:

    NAME                                              STATE     READ WRITE CKSUM
    nas                                               DEGRADED     0     0 49.8K
      raidz1-0                                        DEGRADED     0     0  193K
        gptid/095eaba3-3c9b-11e6-a8b9-d05099c0ff1f    DEGRADED     0     0     0  too many errors
        replacing-1                                   DEGRADED     0     0     0
          130027861328944270                          OFFLINE      0     0     0  was /dev/gptid/0a27642e-3c9b-11e6-a8b9-d05099c0ff1f
          gptid/02fc3662-c33a-11e9-abfd-d05099c38b3b  ONLINE       0     0     0
        gptid/0b0c6d57-3c9b-11e6-a8b9-d05099c0ff1f    DEGRADED     0     0     0  too many errors
        gptid/0be771f2-3c9b-11e6-a8b9-d05099c0ff1f    DEGRADED     0     0     0  too many errors

errors: Permanent errors have been detected in the following files:

        nas/.system/cores:<0x8>
        nas/esx:<0x1>
        <0x187>:<0x30101>
        <0x187>:<0x30302>
        <0x187>:<0x30008>
        <0x187>:<0x30108>
        <0x187>:<0x30308>
        <0x187>:<0x30209>
        <0x187>:<0x3000c>
        <0x187>:<0x3010c>
        <0x187>:<0x3020f>
        <0x187>:<0x30312


From that point I didn't know how to proceed since most of the files had been deleted, but metadata or block data seem to remain.

Concerning the cabling: I didn't open the case but used the host-plug cage to replace the disk. Of course there is still a chance this might have caused hardware issues. But I wonder, if this would result in checksum errors only. Wouldn't it be much more likely to also result in I/O errors reported by zpool or anywhere else in the logs? I can not find any indication of I/O errors anywhere.
 

sretalla

Wizened Sage
Joined
Jan 1, 2016
Messages
5,476
Those metadata items make me want to advise you to get everything off your pool and rebuild it.

If for some reason you can't do that and don't mind taking risks with your data, you could do a zpool clear and sit on it for a while to see what just goes away and what's a real problem, but to me, it looks like you're in for a messy future with the pool as it stands.

If your data is important to you, this is the time to get a good backup if you don't already have one.
 

mbonato

Newbie
Joined
Aug 22, 2019
Messages
3
Since most of the data are backups and the rest is replicated to another FreeNAS I tried the clear option. Eventually, I will rebuild the zpool but for now I would like to find the cause of the CKSUM errors. The result after another resilver is:
Code:
  pool: nas
 state: DEGRADED
status: One or more devices has experienced an error resulting in data
corruption.  Applications may be affected.
action: Restore the file in question if possible.  Otherwise restore the
entire pool from backup.
   see: http://illumos.org/msg/ZFS-8000-8A
  scan: resilvered 2.23T in 0 days 16:43:21 with 33 errors on Fri Aug 23 08:44:11 2019
config:

NAME                                              STATE     READ WRITE CKSUM
nas                                               DEGRADED     0     0 37.2K
  raidz1-0                                        DEGRADED     0     0  149K
    gptid/095eaba3-3c9b-11e6-a8b9-d05099c0ff1f    DEGRADED     0     0     0  too many errors
    replacing-1                                   DEGRADED     0     0     0
      130027861328944270                          OFFLINE      0     0     0  was /dev/gptid/0a27642e-3c9b-11e6-a8b9-d05099c0ff1f
      gptid/02fc3662-c33a-11e9-abfd-d05099c38b3b  ONLINE       0     0     0
    gptid/0b0c6d57-3c9b-11e6-a8b9-d05099c0ff1f    DEGRADED     0     0     0  too many errors
    gptid/0be771f2-3c9b-11e6-a8b9-d05099c0ff1f    ONLINE       0     0     0

errors: Permanent errors have been detected in the following files:

        nas/esx:<0x1>


This looks like resilvering has been successfull this time, but there are unrecoverable erros in one of the datasets. However, the more irritating thing to me are the "too many erros" on two of the disks. SMART data is still fine.

So as far as I understand, the RAID is broken but the hardware is not. How could that happen? For me the RAID completely missed its purpose: Continuous availability even when a single disk fails. Replacing the hard disk and trying to rebuild has consumed more than two days by now and I still need to rebuild the entire RAID configuration and restore the important data from backup.

But the most important question is: What to do to avoid the same situation in future?
 

sretalla

Wizened Sage
Joined
Jan 1, 2016
Messages
5,476
You're using a configuration that's not recommended by the forum (RAIDZ1 with member disks of more than 1TB).

It could be that while your failed disk was still in faulted state, you had some more problems with data errors, which ZFS can detect (with checksums on the healthy disks), but not correct when RAIDZ has no redundant data to go from (RAIDZ1 with 1 disk out).

The forum would recommend that you consider using RAIDZ2 for your pool to avoid that kind of exposure in future.

To make those "too many errors" go away, you can use zpool clear nas. I clearly recommend not doing that and rather rebuilding your pool as RAIDZ2.

It's probably worth noting that you did have continuous pool availability with one disk failed, you just had some data corruption problems for some files (which would probably not have happened with RAIDZ2).
 
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