8

After getting

WARNING: Your hard drive is failing
Device: /dev/sdb [SAT], 1 Offline uncorrectable sectors

I run

$ sudo smartctl -a /dev/sdb
smartctl 6.2 2013-07-26 r3841 [x86_64-linux-3.10.0-514.26.2.el7.x86_64] (local build)
Copyright (C) 2002-13, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF INFORMATION SECTION ===
Device Model:     KingDian S200 60GB
Serial Number:    2017022100551
LU WWN Device Id: 0 000000 000000000
Firmware Version: P0707F1
User Capacity:    60,022,480,896 bytes [60.0 GB]
Sector Size:      512 bytes logical/physical
Rotation Rate:    Solid State Device
Device is:        Not in smartctl database [for details use: -P showall]
ATA Version is:   ACS-2 T13/2015-D revision 3
SATA Version is:  SATA >3.1, 6.0 Gb/s (current: 3.0 Gb/s)
Local Time is:    Tue Oct  3 10:56:08 2017 BST
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:        (  120) seconds.
Offline data collection
capabilities:            (0x11) SMART execute Offline immediate.
                    No Auto Offline data collection support.
                    Suspend Offline collection upon new
                    command.
                    No Offline surface scan supported.
                    Self-test supported.
                    No Conveyance Self-test supported.
                    No Selective Self-test supported.
SMART capabilities:            (0x0002) Does not save 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:    (  10) minutes.

SMART Attributes Data Structure revision number: 1
Vendor Specific SMART Attributes with Thresholds:
ID# ATTRIBUTE_NAME          FLAG     VALUE WORST THRESH TYPE      UPDATED  WHEN_FAILED RAW_VALUE
  1 Raw_Read_Error_Rate     0x0032   100   100   050    Old_age   Always       -       0
  5 Reallocated_Sector_Ct   0x0032   100   100   050    Old_age   Always       -       3
  9 Power_On_Hours          0x0032   100   100   050    Old_age   Always       -       4486
 12 Power_Cycle_Count       0x0032   100   100   050    Old_age   Always       -       13
160 Unknown_Attribute       0x0032   100   100   050    Old_age   Always       -       1
161 Unknown_Attribute       0x0033   100   100   050    Pre-fail  Always       -       98
163 Unknown_Attribute       0x0032   100   100   050    Old_age   Always       -       0
164 Unknown_Attribute       0x0032   100   100   050    Old_age   Always       -       9724
165 Unknown_Attribute       0x0032   100   100   050    Old_age   Always       -       9
166 Unknown_Attribute       0x0032   100   100   050    Old_age   Always       -       1
167 Unknown_Attribute       0x0032   100   100   050    Old_age   Always       -       5
168 Unknown_Attribute       0x0032   100   100   050    Old_age   Always       -       1500
169 Unknown_Attribute       0x0032   100   100   050    Old_age   Always       -       100
175 Program_Fail_Count_Chip 0x0032   100   100   050    Old_age   Always       -       0
176 Erase_Fail_Count_Chip   0x0032   100   100   050    Old_age   Always       -       0
177 Wear_Leveling_Count     0x0032   100   100   050    Old_age   Always       -       9602
178 Used_Rsvd_Blk_Cnt_Chip  0x0032   100   100   050    Old_age   Always       -       3
181 Program_Fail_Cnt_Total  0x0032   100   100   050    Old_age   Always       -       0
182 Erase_Fail_Count_Total  0x0032   100   100   050    Old_age   Always       -       0
192 Power-Off_Retract_Count 0x0032   100   100   050    Old_age   Always       -       13
194 Temperature_Celsius     0x0022   100   100   050    Old_age   Always       -       28
195 Hardware_ECC_Recovered  0x0032   100   100   050    Old_age   Always       -       3994818
196 Reallocated_Event_Count 0x0032   100   100   050    Old_age   Always       -       2414
197 Current_Pending_Sector  0x0032   100   100   050    Old_age   Always       -       3
198 Offline_Uncorrectable   0x0032   100   100   050    Old_age   Always       -       1
199 UDMA_CRC_Error_Count    0x0032   100   100   050    Old_age   Always       -       0
232 Available_Reservd_Space 0x0032   100   100   050    Old_age   Always       -       98
241 Total_LBAs_Written      0x0030   100   100   050    Old_age   Offline      -       36124
242 Total_LBAs_Read         0x0030   100   100   050    Old_age   Offline      -       10259
245 Unknown_Attribute       0x0032   100   100   050    Old_age   Always       -       9799

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%      4486         -

Selective Self-tests/Logging not supported

The detailed smartctl output shows:

$ sudo smartctl -x /dev/sdb
smartctl 6.2 2017-02-27 r4394 [x86_64-linux-3.10.0-514.26.2.el7.x86_64] (local build)
Copyright (C) 2002-13, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF INFORMATION SECTION ===
Device Model:     KingDian S200 60GB
Serial Number:    2017022100551
LU WWN Device Id: 0 000000 000000000
Firmware Version: P0707F1
User Capacity:    60,022,480,896 bytes [60.0 GB]
Sector Size:      512 bytes logical/physical
Rotation Rate:    Solid State Device
Device is:        Not in smartctl database [for details use: -P showall]
ATA Version is:   ACS-2 T13/2015-D revision 3
SATA Version is:  SATA >3.1, 6.0 Gb/s (current: 3.0 Gb/s)
Local Time is:    Tue Oct  3 15:49:27 2017 BST
SMART support is: Available - device has SMART capability.
SMART support is: Enabled
AAM feature is:   Unavailable
APM level is:     128 (minimum power consumption without standby)
Rd look-ahead is: Enabled
Write cache is:   Enabled
ATA Security is:  Disabled, frozen [SEC2]
Wt Cache Reorder: Unavailable

=== 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:        (  120) seconds.
Offline data collection
capabilities:            (0x11) SMART execute Offline immediate.
                    No Auto Offline data collection support.
                    Suspend Offline collection upon new
                    command.
                    No Offline surface scan supported.
                    Self-test supported.
                    No Conveyance Self-test supported.
                    No Selective Self-test supported.
SMART capabilities:            (0x0002) Does not save 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:    (  10) minutes.

SMART Attributes Data Structure revision number: 1
Vendor Specific SMART Attributes with Thresholds:
ID# ATTRIBUTE_NAME          FLAGS    VALUE WORST THRESH FAIL RAW_VALUE
  1 Raw_Read_Error_Rate     -O--CK   100   100   050    -    0
  5 Reallocated_Sector_Ct   -O--CK   100   100   050    -    3
  9 Power_On_Hours          -O--CK   100   100   050    -    4491
 12 Power_Cycle_Count       -O--CK   100   100   050    -    13
160 Unknown_Attribute       -O--CK   100   100   050    -    1
161 Unknown_Attribute       PO--CK   100   100   050    -    98
163 Unknown_Attribute       -O--CK   100   100   050    -    0
164 Unknown_Attribute       -O--CK   100   100   050    -    10068
165 Unknown_Attribute       -O--CK   100   100   050    -    9
166 Unknown_Attribute       -O--CK   100   100   050    -    1
167 Unknown_Attribute       -O--CK   100   100   050    -    5
168 Unknown_Attribute       -O--CK   100   100   050    -    1500
169 Unknown_Attribute       -O--CK   100   100   050    -    100
175 Program_Fail_Count_Chip -O--CK   100   100   050    -    0
176 Erase_Fail_Count_Chip   -O--CK   100   100   050    -    0
177 Wear_Leveling_Count     -O--CK   100   100   050    -    9687
178 Used_Rsvd_Blk_Cnt_Chip  -O--CK   100   100   050    -    3
181 Program_Fail_Cnt_Total  -O--CK   100   100   050    -    0
182 Erase_Fail_Count_Total  -O--CK   100   100   050    -    0
192 Power-Off_Retract_Count -O--CK   100   100   050    -    13
194 Temperature_Celsius     -O---K   100   100   050    -    28
195 Hardware_ECC_Recovered  -O--CK   100   100   050    -    4314392
196 Reallocated_Event_Count -O--CK   100   100   050    -    2667
197 Current_Pending_Sector  -O--CK   100   100   050    -    3
198 Offline_Uncorrectable   -O--CK   100   100   050    -    1
199 UDMA_CRC_Error_Count    -O--CK   100   100   050    -    0
232 Available_Reservd_Space -O--CK   100   100   050    -    98
241 Total_LBAs_Written      ----CK   100   100   050    -    36474
242 Total_LBAs_Read         ----CK   100   100   050    -    10529
245 Unknown_Attribute       -O--CK   100   100   050    -    10146
                            ||||||_ K auto-keep
                            |||||__ C event count
                            ||||___ R error rate
                            |||____ S speed/performance
                            ||_____ O updated online
                            |______ P prefailure warning

General Purpose Log Directory Version 1
SMART           Log Directory Version 1 [multi-sector log support]
Address    Access  R/W   Size  Description
0x00       GPL,SL  R/O      1  Log Directory
0x01           SL  R/O      1  Summary SMART error log
0x02           SL  R/O      1  Comprehensive SMART error log
0x03       GPL     R/O      1  Ext. Comprehensive SMART error log
0x04       GPL,SL  R/O      8  Device Statistics log
0x06           SL  R/O      1  SMART self-test log
0x07       GPL     R/O      1  Extended self-test log
0x10       GPL     R/O      1  NCQ Command Error log
0x11       GPL     R/O      1  SATA Phy Event Counters
0x30       GPL,SL  R/O      9  IDENTIFY DEVICE data log
0x80-0x9f  GPL,SL  R/W     16  Host vendor specific log
0xde       GPL     VS       8  Device vendor specific log

SMART Extended Comprehensive Error Log Version: 1 (1 sectors)
No Errors Logged

SMART Extended Self-test Log Version: 1 (1 sectors)
Num  Test_Description    Status                  Remaining  LifeTime(hours)  LBA_of_first_error
# 1  Extended offline    Completed without error       00%      4488         -
# 2  Extended offline    Completed without error       00%      4487         -
# 3  Extended offline    Completed without error       00%      4486         -

Selective Self-tests/Logging not supported

SCT Commands not supported

Device Statistics (GP Log 0x04)
Page Offset Size         Value  Description
  1  =====  =                =  == General Statistics (rev 1) ==
  1  0x008  4               13  Lifetime Power-On Resets
  1  0x010  4             4491  Power-on Hours
  1  0x018  6       2390408669  Logical Sectors Written
  1  0x020  6         69617191  Number of Write Commands
  1  0x028  6        690041929  Logical Sectors Read
  1  0x030  6          6959725  Number of Read Commands
  7  =====  =                =  == Solid State Device Statistics (rev 1) ==
  7  0x008  1                0  Percentage Used Endurance Indicator

SATA Phy Event Counters (GP Log 0x11)
ID      Size     Value  Description
0x0001  4            0  Command failed due to ICRC error
0x0002  4            0  R_ERR response for data FIS
0x0005  4            1  R_ERR response for non-data FIS
0x000a  4           17  Device-to-host register FISes sent due to a COMRESET
  • 4
    As no ones put it in huge flashing letters yet. IF YOU DON'T HAVE A BACKUP. MAKE ONE NOW – djsmiley2k Oct 3 '17 at 15:17
  • 1
    You can force the drive to remap the bad sector by writing zeroes to it. This guide might help: BadBlockHowto. If you are feeling confident you may skip the debugfs part, and overwrite the block directly with dd if=/dev/zero of=/dev/sdb bs=512 skip={decimal LBA_of_first_error} count=1 oflag=direct,sync – Nazar554 Oct 3 '17 at 16:07
  • @Nazar554 Please refrain from posting answers in comments - for all we know that might be a command that overwrites the entire drive with zeroes and there isn't an ability to downvote comments so if it was it wouldn't be downvoted. – wizzwizz4 Oct 3 '17 at 21:47
10

I have had this issue in the past. IIRC, "Offline uncorrectable sectors" means that the disk controller (the one inside the disk, not the SATA/SCSI controller in your PC) has had repeated read failures with one sector and has decided that it was definitely not usable.

So, I must declare that sector as bad to the filesystem that uses it?

No. Fortunately, today's disks automatically replace bad sectors with good ones taken from a pool of spare sectors. Thus, you don't have to declare those bad sectors to your filesystem so that it doesn't use them anymore. Of course, the size of that pool is limited (Available_Reservd_Space sectors, I guess) and once all spare sectors have been used, bad sectors will remain unusable and you will have to declare them as such to your FS.

So, everything is fine, this is a harmless message?

Not really. Your drive has tried several times to read the bad sector, and failed every time; so it's been queued up for replacement, but the drive can't do that on its own (it keeps hoping it will eventually be able to read it). Until the sector is overwritten with new data, it will remain "uncorrectable"; once it is overwritten, or if the drive somehow manages to read it, it will be remapped and replaced with a spare sector (in the smartctl output, Offline_Uncorrectable will be decremented by 1 and Reallocated_Sector_Ct will be incremented by 1).

What can I do?

In such an event, I usually force my RAID 1 array to resync (good disk -> faulty disk) in order for that new sector to have the right content. In any case, do a fsck and, if you have a backup of that partition (you should), compare the backup to your actual content.

  • One important thing to keep in mind is that the appearance of an "offline uncorrectable" is a warning sign that the drive may fail completely in the near future. – Mark Oct 3 '17 at 21:01
4

Run a long smartctl test, if it comes back positive for errors you have a problem, if not it should be fine to use the hardrive.

smartctl -t long /dev/sdb

Note: Remember to backup the data in your hardrive before testing it, depending on the condition of your drive, the stress from the test could damage your disk further.

Use Diskscan to try and fix the uncorrectable sectors if you have errors with your smartctl test.

  • 2
    But first backup your valuable data. Because the testing brings additional stress to your disk and if it's in bad condition, the problem may get much worse quickly. – Jaroslav Kucera Oct 3 '17 at 10:49
  • @JaroslavKucera I don't seem to get errors, but the warning messages – Manolete Oct 3 '17 at 14:52

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