LS220D - Accessing SMART data

[MymsMan]

Recently my NAS reported a disk error and went into degraded mode,
Recommendation was to replace disk but the cost for a new 2TB disk is about the same as I paid for the 4TB NAS a few years ago ☹️

The Buffalo software was very vague about the nature of the error so I pulled the disk and attached it via USB to a Linux machine to see if the SMART data had more detail but it appears the disk does not support SMART

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smartctl -a /dev/sdc1
smartctl 6.4 2015-06-04 r4109 [7405b0-smp-linux-2.6.18-7.1] (local build)
Copyright (C) 2002-15, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF INFORMATION SECTION ===
Vendor:               WDC WD20
Product:              EZRZ-22Z5HB0
Revision:             4101
Compliance:           SPC-4
User Capacity:        2,000,398,934,016 bytes [2.00 TB]
Logical block size:   512 bytes
LB provisioning type: unreported, LBPME=-1, LBPRZ=0
Logical Unit id:      0x3023567832183100
Serial number:        235678C218CA
Device type:          disk
Local Time is:        Sat Oct 17 22:15:13 2026 BST
SMART support is:     Unavailable - device lacks SMART capability.

=== START OF READ SMART DATA SECTION ===

Error Counter logging not supported

No self-tests have been loggedIs this normal?
The disk model shows as a WD Blue drive and according to WD all WD drives support S.M.A.R.T
Why would a NAS drive not have S.M.A.R.T. enabled?

I have since rebuilt the Raid array using the same drive and, touch wood, it is working correctly with no further disk errors reported

[MymsMan]

User error!  Specified SDC1 instead of SDC

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smartctl -d sat -a /dev/sdc
smartctl 6.4 2015-06-04 r4109 [7405b0-smp-linux-2.6.18-7.1] (local build)
Copyright (C) 2002-15, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF INFORMATION SECTION ===
Device Model:     WDC WD20EZRZ-22Z5HB0
Serial Number:    WD-WCC4M3JPD66E
LU WWN Device Id: 5 0014ee 2badda8a6
Firmware Version: 80.00A80
User Capacity:    2,000,398,934,016 bytes [2.00 TB]
Sector Sizes:     512 bytes logical, 4096 bytes physical
Rotation Rate:    5400 rpm
Device is:        Not in smartctl database [for details use: -P showall]
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:    Mon Oct 19 11:45:03 2026 BST
SMART support is: Available - device has SMART capability.
SMART support is: Enabled

=== START OF READ SMART DATA SECTION ===
SMART Status command failed
Please get assistance from http://smartmontools.sourceforge.net/
Register values returned from SMART Status command are:
 ERR=0x00, SC=0x00, LL=0x00, LM=0x00, LH=0x00, DEV=0x00, STS=0x00
SMART Status not supported: Invalid ATA output register values
SMART overall-health self-assessment test result: PASSED
Warning: This result is based on an Attribute check.

General SMART Values:
Offline data collection status:  (0x82) Offline data collection activity
                                        was completed without error.
                                        Auto Offline Data Collection: Enabled.
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:                (26580) 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:        ( 268) 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       -       0
  3 Spin_Up_Time            0x0027   174   174   021    Pre-fail  Always       -       4266
  4 Start_Stop_Count        0x0032   100   100   000    Old_age   Always       -       72
  5 Reallocated_Sector_Ct   0x0033   200   200   140    Pre-fail  Always       -       0
  7 Seek_Error_Rate         0x002e   197   197   000    Old_age   Always       -       765
  9 Power_On_Hours          0x0032   041   041   000    Old_age   Always       -       43670
 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       -       68
192 Power-Off_Retract_Count 0x0032   200   200   000    Old_age   Always       -       57
193 Load_Cycle_Count        0x0032   001   001   000    Old_age   Always       -       6192692
194 Temperature_Celsius     0x0022   119   107   000    Old_age   Always       -       28
196 Reallocated_Event_Count 0x0032   200   200   000    Old_age   Always       -       0
197 Current_Pending_Sector  0x0032   195   195   000    Old_age   Always       -       1631
198 Offline_Uncorrectable   0x0030   196   196   000    Old_age   Offline      -       1617
199 UDMA_CRC_Error_Count    0x0032   200   200   000    Old_age   Always       -       0
200 Multi_Zone_Error_Rate   0x0008   196   196   000    Old_age   Offline      -       1710

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.
Running a short test resulted in:

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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%     43670         2090007024
Also wondering why SMART status command failed

Google interpretation of results
Your hard drive is actively failing and is unsafe to use. You need to back up any critical data immediately and stop using the drive for active storage.

🚨 The Critical Red Flags

While your reallocated sector count is currently 0, the drive is failing to read physical magnetic sectors on the platters:
• ID 197 Current_Pending_Sector = 1631: There are 1,631 unstable sectors waiting to be remapped. The drive tried to read these sectors, failed, and has flagged them as "danger zones."
• ID 198 Offline_Uncorrectable = 1617: The drive's internal offline testing confirmed 1,617 sectors are completely unreadable and cannot be recovered by the drive's built-in error correction logic.
• ID 200 Multi_Zone_Error_Rate = 1710: There have been 1,710 errors while attempting to write data to the drive. This indicates serious physical degradation of the platter surface or the recording heads.

⏱️ The Drive's History & Lifespan

• ID 9 Power_On_Hours = 43,670: This drive has been running for 4.98 years of continuous power-on time. Mechanical hard drives typically begin showing high failure rates after 3 to 5 years.
• ID 193 Load_Cycle_Count = 6,192,692: Western Digital Green/Blue drives are rated for 300,000 head parks. Due to aggressive power management firmware, your drive has parked its heads over 6 million times—vastly exceeding its mechanical design limit.

[1000001101000]

The summary sounds about right, most likely a drive dying of old age.

I'd make sure it was connected to stable power while testing, some drive errors can be false-positive if the drive is having problems that aren't specific to the drive itself like if the power supply is failing or undersized. 

Likewise, if you try writing 0's and/or random data to the drive using

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badblocks you'll either see the pending sectors convert to reallocated sectors (likely worn out or damaged) or go away (possibly the problem wasn't permanent).

Just given the age I don't know that I would trust it much even if the errors did clear up, but it could be useful learning exercise.