Disk failing, but volume is OK. How ?

[Adith Sudhakar]

I have 2 WD Red Drives 3 TB in mirror configuration and the volume is reported as being healthy.

However, I see a lot of

Code:

ahcich1: Error while READ LOG EXT
(ada0:ahcich1:0:0:0): READ_FPDMA_QUEUED. ACB: 60 d0 10 8d 32 40 46 00 00 00 00 00
(ada0:ahcich1:0:0:0): CAM status: ATA Status Error
(ada0:ahcich1:0:0:0): ATA status: 00 ()
(ada0:ahcich1:0:0:0): RES: 00 00 00 00 00 00 00 00 00 00 00
(ada0:ahcich1:0:0:0): Error 5, Retries exhausted

and SMART results show:

Code:

smartctl 6.3 2014-07-26 r3976 [FreeBSD 9.3-RELEASE-p13 amd64] (local build)
Copyright (C) 2002-14, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF INFORMATION SECTION ===
Model Family:     Western Digital Red (AF)
Device Model:     WDC WD30EFRX-68EUZN0
Serial Number:    WD-WCC4N4HUCVPV
LU WWN Device Id: 5 0014ee 20bbb9649
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:    Sat Jun  6 11:21:47 2015 PDT
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: FAILED!
See vendor-specific Attribute list for failed Attributes.

General SMART Values:
Offline data collection status:  (0x00)    Offline data collection activity
                    was never started.
                    Auto Offline Data Collection: Disabled.
Self-test execution status:      (  73)    The previous self-test completed having
                    a test element that failed and the test
                    element that failed is not known.
Total time to complete Offline
data collection:         (41160) 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:      ( 413) 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   114   114   051    Pre-fail  Always       -       2260
  3 Spin_Up_Time            0x0027   181   180   021    Pre-fail  Always       -       5908
  4 Start_Stop_Count        0x0032   100   100   000    Old_age   Always       -       28
  5 Reallocated_Sector_Ct   0x0033   138   138   140    Pre-fail  Always   FAILING_NOW 1823
  7 Seek_Error_Rate         0x002e   189   189   000    Old_age   Always       -       637
  9 Power_On_Hours          0x0032   099   099   000    Old_age   Always       -       806
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       -       28
192 Power-Off_Retract_Count 0x0032   200   200   000    Old_age   Always       -       18
193 Load_Cycle_Count        0x0032   200   200   000    Old_age   Always       -       20
194 Temperature_Celsius     0x0022   122   119   000    Old_age   Always       -       28
196 Reallocated_Event_Count 0x0032   164   164   000    Old_age   Always       -       36
197 Current_Pending_Sector  0x0032   066   066   000    Old_age   Always       -       65532
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  Extended offline    Completed: unknown failure    90%       806         -
# 2  Short offline       Completed: unknown failure    90%       806         -

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.

which clearly shows my drive is failing.

If that is the case, why am I not seeing that the drive has failed in the GUI ?

 

[joeschmuck]

Replace your drive, it is dying fast! IDs 5, 196, and 197 are telling you this. Use the user manual in order to replace the drive properly. I'd also backup any important data to external storage right now and then turn off your NAS until you have a replacement hard drive. Your drive should be under warranty with only 800 hours on it. I'd fill out the RMA on it and use the prepay option to have them ship you a drive before you return the failed one.

 

[joeschmuck]

WD Warranty Checker is offline today until 6:30 PM so I'd just check it tomorrow.

 

[Ericloewe]

If that is the case, why am I not seeing that the drive has failed in the GUI ?

The drive is still functioning well enough (from ZFS' point of view) to not be worth dropping from the array. That doesn't mean it's actually working, only that it's been responding normally to most of ZFS' requests.

 

[joeschmuck]

SMART was designed to tell you that your drive is going to fail because of certain factors. So it appears you have physical errors occurring to the platters based on the SMART data you provided. So the idea behind SMART is it warns you before it's too late, if it's possible because some problem are instantly catastrophic like an electronic failure and happens in an instant so SMART can't help you there. You have been given a warning that your drive is failing and your drive is moving data around on the hard drive to areas not affected, but it is dying. When it does die, you will see it in the GUI. I run a short SMART test every evening on all my drives.

 

[Adith Sudhakar]

Given that I have it in mirrored setup, I do not have to take a backup am i right ?

 

[Robert Trevellyan]

Given that I have it in mirrored setup, I do not have to take a backup am i right ?

The reason you've been counseled to backup your data now is that if that drive dies before you replace it, you'll have no redundancy in your pool and will thus lose data if anything bad happens to the remaining drive. A backup would give you redundancy.

 

[DrKK]

Indeed. Mirrors are not backups. If you lose this drive, then your data is in code red mode until you get a new one.

This is why I always have a cold spare on the rack. If you don't have a replacement ready to go, then back up any data you can't afford to lose, now, just in case.