2 Currently unreadable sectors on drive?

[icsy7867]

I currently have a RaidZ2 (6x 3TB Drives) so I am in no immediate danger. But I am having trouble tracking down this error in the GUI.

Freenas GUI is telling me:

Code:

Device: /dev/ada6, 2 Currently unreadable (pending) sectors

So I decide to fire off a long SMART test

Code:

smartctl -t long /dev/ada6

and then read the output

Code:

smartctl -a /dev/ada6

But I dont see anything about bad sectors here. Should I have the addresses under "LBA_of_first_error"?

Code:

=== START OF INFORMATION SECTION ===
Model Family:     Western Digital Red
Device Model:     WDC WD30EFRX-68EUZN0
Serial Number:    WD-WCC4N2LFSCCS
LU WWN Device Id: 5 0014ee 264270370
Firmware Version: 82.00A82
User Capacity:    3,000,592,982,016 bytes [3.00 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 Jan 23 06:22:38 2019 PST
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:                (38580) 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:        ( 387) 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       -       77
  3 Spin_Up_Time            0x0027   180   180   021    Pre-fail  Always       -       5991
  4 Start_Stop_Count        0x0032   100   100   000    Old_age   Always       -       27
  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   085   085   000    Old_age   Always       -       11339
 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       -       27
192 Power-Off_Retract_Count 0x0032   200   200   000    Old_age   Always       -       12
193 Load_Cycle_Count        0x0032   200   200   000    Old_age   Always       -       380
194 Temperature_Celsius     0x0022   118   109   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       -       2
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  Extended offline    Completed without error       00%     11329         -
# 2  Extended offline    Completed without error       00%     10993         -
# 3  Short offline       Completed without error       00%     10810         -
# 4  Extended offline    Completed without error       00%     10097         -
# 5  Short offline       Completed without error       00%      9967         -
# 6  Extended offline    Completed without error       00%      9423         -
# 7  Extended offline    Completed without error       00%      8753         -
# 8  Extended offline    Completed without error       00%      7913         -
# 9  Short offline       Completed without error       00%      7450         -
#10  Extended offline    Completed without error       00%      7241         -
#11  Extended offline    Completed without error       00%      2221         -
#12  Extended offline    Completed without error       00%      1381         -
#13  Short offline       Completed without error       00%       919         -
#14  Extended offline    Completed without error       00%       710         -

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.

 

[Johnny Fartpants]

197 Current_Pending_Sector 0x0032 200 200 000 Old_age Always - 2

Replace the drive

 

[danb35]

Replace the drive

Eh, maybe. I'm not convinced that bad sectors in the low single digits, without other symptoms, are grounds for immediate disk replacement.

@icsy7867, check out https://forums.freenas.org/index.ph...bleshooting-guide-all-versions-of-freenas.17/

 

[RickH]

But I don't see anything about bad sectors here. Should I have the addresses under "LBA_of_first_error"?

'Errors' are only reported if there is actually a problem reading or writing data - in this case SMART is doing it's job of alerting you that there are some bad sectors; however, the internal correction measures in the drive have also done their job and prevented those bad sectors from translating into actual read/write errors.

As for whether or not that particular drive needs immediate replacement - that's really for you to decide. There are plenty of statistical studies that show that an increase in SMART 197 to anything over 0 means that the drive is more likely to fail; however, there are plenty of drives out there that have been operating for years with a few bad sectors...

I typically schedule my drives for replacement as soon as they start throwing SMART errors - but in a case that that, I probably wouldn't make a special trip to the data center just to swap out that one drive. If you have immediate access to the server, you're probably safe in 'letting it ride' as your RAIDZ2 protects you from up to 2 drive failures in your vdev and a new 3TB SATA drive should be relatively easy to procure - but again, it's really up to you and what you're comfortable with.

 

[Erwin]

In my opinion (and experience) this is no reason for panic.
Your drive is just in the middle of the repair process of a potentially bad sector. Just 2 suspect sectors is no head crash, and they will either disappear again or manifest as reallocated sectors. And having reallocated sectors is a normal process for a hard drive. But when the count increases rapidly, then it is time to be concerned...
Did ZFS scrub the volumes since you discovered the unreadable sector message for the first time?
https://en.wikipedia.org/wiki/S.M.A.R.T.#Known_ATA_S.M.A.R.T._attributes

BR
erwin

 

[Jailer]

As others have stated, I wouldn't be too concerned about that drive at this point. Just watch it closely and if it gets worse then replace it.

What this does present is an opportunity to procure a replacement if you haven't already and get it tested and burned in and ready to go just in case da6 decide to go tango uniform.