Failed Drive Recovery

TrueNAS General
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1

The Situation: I have a drive in my pool that is listed as ‘Removed’ due to being unhealthy, even though it appears to pass a short SMART test. The pool is now in a degraded state and showing four of the remaining good disks as ‘resilvering’.

The Question: Is it safe to power down the NAS and swap out the failed drive while the pool is resilvering or should I wait for it to finish?

Disk Info (drive with errors highlighted):

image
image2268×529 27.9 KB

zpool status -vx output:

  pool: The Hoard
 state: DEGRADED
status: One or more devices is currently being resilvered.  The pool will
        continue to function, possibly in a degraded state.
action: Wait for the resilver to complete.
  scan: resilver in progress since Sat Mar 14 12:19:16 2026
        3.76T / 54.1T scanned at 6.50G/s, 0B / 50.4T issued
        7.14M resilvered, 0.00% done, no estimated completion time
expand: expanded raidz1-0 copied 34.0T in 18:51:32, on Tue Nov  4 06:44:36 2025
config:

        NAME                                      STATE     READ WRITE CKSUM
        The Hoard                                 DEGRADED     0     0     0
          raidz1-0                                DEGRADED 2.51K 1.11K     0
            6784c3af-de11-400c-85e1-73119e0e8a50  REMOVED      0     0     0
            6221a190-0069-4833-8082-901117bbc152  ONLINE   2.10K 1.27K     0
            f5edd9c1-9b93-4fa5-b9c2-aa68a03d9d0a  ONLINE       0     0     0  (resilvering)
            a909f20e-ac31-45a4-b295-47849d1393fb  ONLINE   1.56K 1.04K     0
            d1003ab8-018e-4cdf-bb39-99e0b9444505  ONLINE       0     0     0  (resilvering)
            da8c68c0-ddf3-474b-8236-5d60f24c00d5  ONLINE       0     0     0
            a2874c99-a790-45db-9ed2-a4efa918559f  ONLINE       0     0     0
            4d249df5-dca8-4345-ab48-5a4552dc05eb  ONLINE       0     0     0  (resilvering)
            0d241af5-beca-49fd-be4e-5452e8c4acc4  ONLINE       0     0     0  (resilvering)

errors: List of errors unavailable: pool I/O is currently suspended

dmesg -H error (showing multiple times for different sectors on this drive):

[  +0.000003] I/O error, dev sdf, sector 15628052512 op 0x0:(READ) flags 0x800 phys_seg 28 prio class 0
[  +0.000076] sd 0:0:8:0: [sdf] tag#8645 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_OK cmd_age=0s
[  +0.000164] sd 0:0:8:0: [sdf] tag#8645 Sense Key : Not Ready [current] 
[  +0.000003] sd 0:0:8:0: [sdf] tag#8645 Add. Sense: Logical unit not ready, cause not reportable
[  +0.000002] sd 0:0:8:0: [sdf] tag#8645 CDB: Read(16) 88 00 00 00 00 03 a3 81 26 20 00 00 00 e0 00 00

smartctl -a results:

=== START OF INFORMATION SECTION ===
Model Family:     Seagate IronWolf
Device Model:     ST8000VN004-3CP101
Serial Number:    WWZ40A39
LU WWN Device Id: 5 000c50 0e8081cef
Firmware Version: SC60
User Capacity:    8,001,563,222,016 bytes [8.00 TB]
Sector Sizes:     512 bytes logical, 4096 bytes physical
Rotation Rate:    7200 rpm
Form Factor:      3.5 inches
Device is:        In smartctl database 7.3/5528
ATA Version is:   ACS-4 (minor revision not indicated)
SATA Version is:  SATA 3.3, 6.0 Gb/s (current: 6.0 Gb/s)
Local Time is:    Sat Mar 14 12:39:09 2026 CST
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:  (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:                (  559) 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:        (   1) minutes.
Extended self-test routine
recommended polling time:        ( 693) minutes.
Conveyance self-test routine
recommended polling time:        (   2) minutes.
SCT capabilities:              (0x50bd) SCT Status supported.
                                        SCT Error Recovery Control supported.
                                        SCT Feature Control supported.
                                        SCT Data Table supported.

SMART Attributes Data Structure revision number: 10
Vendor Specific SMART Attributes with Thresholds:
ID# ATTRIBUTE_NAME          FLAG     VALUE WORST THRESH TYPE      UPDATED  WHEN_FAILED RAW_VALUE
  1 Raw_Read_Error_Rate     0x000f   078   064   044    Pre-fail  Always       -       62442624
  3 Spin_Up_Time            0x0003   097   091   000    Pre-fail  Always       -       0
  4 Start_Stop_Count        0x0032   099   099   020    Old_age   Always       -       2009
  5 Reallocated_Sector_Ct   0x0033   100   100   010    Pre-fail  Always       -       0
  7 Seek_Error_Rate         0x000f   086   060   045    Pre-fail  Always       -       430950864
  9 Power_On_Hours          0x0032   090   090   000    Old_age   Always       -       9259
 10 Spin_Retry_Count        0x0013   100   100   097    Pre-fail  Always       -       0
 12 Power_Cycle_Count       0x0032   099   099   020    Old_age   Always       -       2009
 18 Head_Health             0x000b   100   100   050    Pre-fail  Always       -       0
187 Reported_Uncorrect      0x0032   100   100   000    Old_age   Always       -       0
188 Command_Timeout         0x0032   100   099   000    Old_age   Always       -       8590065669
190 Airflow_Temperature_Cel 0x0022   051   032   000    Old_age   Always       -       49 (Min/Max 48/49)
192 Power-Off_Retract_Count 0x0032   100   100   000    Old_age   Always       -       1987
193 Load_Cycle_Count        0x0032   098   098   000    Old_age   Always       -       4992
194 Temperature_Celsius     0x0022   049   068   000    Old_age   Always       -       49 (0 24 0 0 0)
197 Current_Pending_Sector  0x0012   100   100   000    Old_age   Always       -       0
198 Offline_Uncorrectable   0x0010   100   100   000    Old_age   Offline      -       0
199 UDMA_CRC_Error_Count    0x003e   200   200   000    Old_age   Always       -       0
240 Head_Flying_Hours       0x0000   100   100   000    Old_age   Offline      -       8612h+57m+34.421s
241 Total_LBAs_Written      0x0000   100   253   000    Old_age   Offline      -       107750888480
242 Total_LBAs_Read         0x0000   100   253   000    Old_age   Offline      -       316712971685

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%      9258         -
# 2  Short offline       Completed without error       00%      8949         -
# 3  Short offline       Completed without error       00%      8426         -
# 4  Short offline       Completed without error       00%      7971         -
# 5  Short offline       Completed without error       00%      7227         -
# 6  Short offline       Completed without error       00%      6513         -
# 7  Short offline       Completed without error       00%      5769         -
# 8  Short offline       Completed without error       00%      5049         -
# 9  Short offline       Completed without error       00%      4305         -
#10  Short offline       Completed without error       00%      3561         -
#11  Short offline       Completed without error       00%      2841         -
#12  Short offline       Completed without error       00%      2097         -
#13  Extended offline    Completed without error       00%      1478         -
#14  Short offline       Completed without error       00%      1378         -
#15  Short offline       Completed without error       00%       634         -

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.

The above only provides legacy SMART information - try 'smartctl -x' for more
2

First, stop assuming a SMART Short test is the same as a Long/Extended test, they are different. Run a SMART Long test on your drives. Make sure they pass (no errors). Based on the data provided, the drive look fine, however the Long test must be run to cover your bases.

If the drive passes, then realize that you have a ZFS or System Stability issue.

Most of your drives are Resilvering, this is not a good situation, especially with a RAIDZ1. But if they are all resilvering, something had to have happened. The loss of a single drive would not cause this to happen.

Do you have a backup of your data,at least anything important? You are one drive failure away from a full loss.

I’m not the expert on Resilvering, and I don’t know off the top of my head what this means errors: List of errors unavailable: pool I/O is currently suspended but a quick internet search tells me the pool is offline while it tries to recover.

My advice, let it complete the resilvering. If you do have access the your data and now.

Hopefully someone else chimes in and either says they agree with me, or they don’t and why. I don’t know it all.

1 Like
3

:index_pointing_up:
Yep, you have a troubled raidz1 that has issues on multiple drives, and is too wide for comfort. Also sda is rather toasty at 49°C. What’s the hardware? Is there a HBA? Or some “SATA card”?

1 Like
4

Here’s the parts list: Your Account - PCPartPicker

And Here’s the LSI card I’m using: Amazon.com: YiBaoTong LSI SAS2308 9207-8i HBA Card 6Gbs SAS SATA PCI-E 3.0 HBA LSI FW:P20 IT Mode Expander Card ZFS FreeNAS unRAID+ 2 * SFF-8087-4* SATA Cable : Electronics

Cooling isn’t the best in the rack currently. Working towards resolving that as soon as possible.

As for backups, unfortunately, I don’t. I don’t have a second storage space large enough. I know this is a fail on my part, just poor budgeting choices during the initial buildout.

5

Consumer motherboard in (consumer-minded?) 4U rack. A rather unhealthy mix.

Noctua fans are most inadequate to cool a rack: High-pressure screamers are required here.
I suspect that your HBA is overheating, and you’re lucky that errors are confined to a few drives rather than spread over the whole array.

My advice would be shut down the NAS and do not restart until you have improved cooling. At the very least, make sure that the HBA is cool. (Also run MemTest to make sure there isn’t an issue with the non-ECC RAM: That would be the other “usual suspect” for multiple errors on apparently healthy drives.)

And think hard about backing up the most critical data in there.

1 Like
6

We all tend to learn the hard way, and hopefully only once. Some of us it takes a few losses, mine wasn’t with a NAS, it was the loss of programs not being saved frequently and a crash means loss of the past 6 hours of work. No fun. Hopefully you will create a new RAIDZ2 pool, redundancy maters if the data is remotely important.

Looking at the case, it looks like a desktop case with rack mounting tabs. The airflow path is very limited based on the photos.

As @etorix pointed out, the HBA requires a LOT of airflow to cool it. I too suspect the HBA is overheating. And the drives are a bit warm. 49C isn’t horrible, if the drive is doing a Resilver, they will heat up with all that activity, however public opinion is anything over 40C is probably too high. My spinners are allowed to get to 42C, but normally run under 40C.

Back to airflow, you may need a case designed for high airflow or just modify the case you have. You should have fans in front of all your spinning drives, forcing air out the rear of the case. If you have the room, mount the drives so there is more space between them. If you can’t do that, at least try to space the drives were a fan is not directly in front of it.

And also run the system stability tests (Memtest86+ and Prime95) to ensure your hardware is stable.