0

I have two servers that are set up exactly the same way (same SSD's, RAM etc.). They both have ESXI running on them. One of the boxes had a quest host that had a lot of complaints about writing to the disk. It turns out that the host did not have enough RAM and was going heavy into swap. This would explain why we saw the errors. The SSD was being used as ram and could not keep up.I launched several instances of

dd bs=2GB if=/dev/zero of=/dev/null 

On the box to cause the box to go into swap so the SSD would be used as ram. On box1 (where we had the issue) it took a lot of effort but we were able to trigger the same errors. On box2 we ran the same tests over and over and only once did we successfully get an error. This lead me to believe that the issue was with the disk on box1. I used fdisk as well as look at smartd and the reports for both systems seem to indicate that disks were OK. am I missing something here?

box1 (bad box):

smartctl 7.1 2019-12-30 r5022 [x86_64-linux-5.4.0-26-generic] (local build)
Copyright (C) 2002-19, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF READ SMART DATA SECTION ===
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   100   100   000    Pre-fail  Always       -       0
  5 Reallocate_NAND_Blk_Cnt 0x0032   100   100   010    Old_age   Always       -       0
  9 Power_On_Hours          0x0032   100   100   000    Old_age   Always       -       131
 12 Power_Cycle_Count       0x0032   100   100   000    Old_age   Always       -       24
171 Program_Fail_Count      0x0032   100   100   000    Old_age   Always       -       0
172 Erase_Fail_Count        0x0032   100   100   000    Old_age   Always       -       0
173 Ave_Block-Erase_Count   0x0032   100   100   000    Old_age   Always       -       12
174 Unexpect_Power_Loss_Ct  0x0032   100   100   000    Old_age   Always       -       20
180 Unused_Reserve_NAND_Blk 0x0033   000   000   000    Pre-fail  Always       -       48
183 SATA_Interfac_Downshift 0x0032   100   100   000    Old_age   Always       -       0
184 Error_Correction_Count  0x0032   100   100   000    Old_age   Always       -       0
187 Reported_Uncorrect      0x0032   100   100   000    Old_age   Always       -       0
194 Temperature_Celsius     0x0022   064   049   000    Old_age   Always       -       36 (Min/Max 0/51)
196 Reallocated_Event_Count 0x0032   100   100   000    Old_age   Always       -       0
197 Bogus_Current_Pend_Sect 0x0032   100   100   000    Old_age   Always       -       0
198 Offline_Uncorrectable   0x0030   100   100   000    Old_age   Offline      -       0
199 UDMA_CRC_Error_Count    0x0032   100   100   000    Old_age   Always       -       665
202 Percent_Lifetime_Remain 0x0030   100   100   001    Old_age   Offline      -       0
206 Write_Error_Rate        0x000e   100   100   000    Old_age   Always       -       0
210 Success_RAIN_Recov_Cnt  0x0032   100   100   000    Old_age   Always       -       0
246 Total_LBAs_Written      0x0032   100   100   000    Old_age   Always       -       3801713422
247 Host_Program_Page_Count 0x0032   100   100   000    Old_age   Always       -       62354066
248 FTL_Program_Page_Count  0x0032   100   100   000    Old_age   Always       -       39135457

root@ubuntu:~# smartctl --all /dev/sda
smartctl 7.1 2019-12-30 r5022 [x86_64-linux-5.4.0-26-generic] (local build)
Copyright (C) 2002-19, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF INFORMATION SECTION ===
Model Family:     Crucial/Micron MX500 SSDs
Device Model:     CT500MX500SSD1
Serial Number:    2002E2330303
LU WWN Device Id: 5 00a075 1e2330303
Firmware Version: M3CR023
User Capacity:    500,107,862,016 bytes [500 GB]
Sector Sizes:     512 bytes logical, 4096 bytes physical
Rotation Rate:    Solid State Device
Form Factor:      2.5 inches
Device is:        In smartctl database [for details use: -P show]
ATA Version is:   ACS-3 T13/2161-D revision 5
SATA Version is:  SATA 3.3, 6.0 Gb/s (current: 6.0 Gb/s)
Local Time is:    Mon Jul 20 09:34:19 2020 UTC

==> WARNING: This firmware returns bogus raw values in attribute 197

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: (    0) 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: (  30) minutes.
Conveyance self-test routine
recommended polling time: (   2) minutes.
SCT capabilities:       (0x0031) 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   100   100   000    Pre-fail  Always       -       0
  5 Reallocate_NAND_Blk_Cnt 0x0032   100   100   010    Old_age   Always       -       0
  9 Power_On_Hours          0x0032   100   100   000    Old_age   Always       -       131
 12 Power_Cycle_Count       0x0032   100   100   000    Old_age   Always       -       24
171 Program_Fail_Count      0x0032   100   100   000    Old_age   Always       -       0
172 Erase_Fail_Count        0x0032   100   100   000    Old_age   Always       -       0
173 Ave_Block-Erase_Count   0x0032   100   100   000    Old_age   Always       -       12
174 Unexpect_Power_Loss_Ct  0x0032   100   100   000    Old_age   Always       -       20
180 Unused_Reserve_NAND_Blk 0x0033   000   000   000    Pre-fail  Always       -       48
183 SATA_Interfac_Downshift 0x0032   100   100   000    Old_age   Always       -       0
184 Error_Correction_Count  0x0032   100   100   000    Old_age   Always       -       0
187 Reported_Uncorrect      0x0032   100   100   000    Old_age   Always       -       0
194 Temperature_Celsius     0x0022   064   049   000    Old_age   Always       -       36 (Min/Max 0/51)
196 Reallocated_Event_Count 0x0032   100   100   000    Old_age   Always       -       0
197 Bogus_Current_Pend_Sect 0x0032   100   100   000    Old_age   Always       -       0
198 Offline_Uncorrectable   0x0030   100   100   000    Old_age   Offline      -       0
199 UDMA_CRC_Error_Count    0x0032   100   100   000    Old_age   Always       -       665
202 Percent_Lifetime_Remain 0x0030   100   100   001    Old_age   Offline      -       0
206 Write_Error_Rate        0x000e   100   100   000    Old_age   Always       -       0
210 Success_RAIN_Recov_Cnt  0x0032   100   100   000    Old_age   Always       -       0
246 Total_LBAs_Written      0x0032   100   100   000    Old_age   Always       -       3801713422
247 Host_Program_Page_Count 0x0032   100   100   000    Old_age   Always       -       62354066
248 FTL_Program_Page_Count  0x0032   100   100   000    Old_age   Always       -       39135459

SMART Error Log Version: 1
Warning: ATA error count 0 inconsistent with error log pointer 1

ATA Error Count: 0
CR = Command Register [HEX]
FR = Features Register [HEX]
SC = Sector Count Register [HEX]
SN = Sector Number Register [HEX]
CL = Cylinder Low Register [HEX]
CH = Cylinder High Register [HEX]
DH = Device/Head Register [HEX]
DC = Device Command Register [HEX]
ER = Error register [HEX]
ST = Status register [HEX]
Powered_Up_Time is measured from power on, and printed as
DDd+hh:mm:SS.sss where DD=days, hh=hours, mm=minutes,
SS=sec, and sss=millisec. It "wraps" after 49.710 days.

Error 0 occurred at disk power-on lifetime: 0 hours (0 days + 0 hours)
  When the command that caused the error occurred, the device was in an unknown state.

  After command completion occurred, registers were:
  ER ST SC SN CL CH DH
  -- -- -- -- -- -- --
  00 ec 00 00 00 00 00

  Commands leading to the command that caused the error were:
  CR FR SC SN CL CH DH DC   Powered_Up_Time  Command/Feature_Name
  -- -- -- -- -- -- -- --  ----------------  --------------------
  ec 00 00 00 00 00 00 00      00:00:00.000  IDENTIFY DEVICE
  ec 00 00 00 00 00 00 00      00:00:00.000  IDENTIFY DEVICE
  ec 00 00 00 00 00 00 00      00:00:00.000  IDENTIFY DEVICE
  ec 00 00 00 00 00 00 00      00:00:00.000  IDENTIFY DEVICE
  c8 00 00 00 00 00 00 00      00:00:00.000  READ DMA

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%       121         -

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 dela```




box2 (good box)

```root@ubuntu:/usr/src/gsmartcontrol-1.1.3# smartctl -A /dev/sda
smartctl 7.1 2019-12-30 r5022 [x86_64-linux-5.4.0-26-generic] (local build)
Copyright (C) 2002-19, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF READ SMART DATA SECTION ===
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   100   100   000    Pre-fail  Always       -       0
  5 Reallocate_NAND_Blk_Cnt 0x0032   100   100   010    Old_age   Always       -       0
  9 Power_On_Hours          0x0032   100   100   000    Old_age   Always       -       295
 12 Power_Cycle_Count       0x0032   100   100   000    Old_age   Always       -       20
171 Program_Fail_Count      0x0032   100   100   000    Old_age   Always       -       0
172 Erase_Fail_Count        0x0032   100   100   000    Old_age   Always       -       0
173 Ave_Block-Erase_Count   0x0032   099   099   000    Old_age   Always       -       28
174 Unexpect_Power_Loss_Ct  0x0032   100   100   000    Old_age   Always       -       13
180 Unused_Reserve_NAND_Blk 0x0033   000   000   000    Pre-fail  Always       -       36
183 SATA_Interfac_Downshift 0x0032   100   100   000    Old_age   Always       -       0
184 Error_Correction_Count  0x0032   100   100   000    Old_age   Always       -       0
187 Reported_Uncorrect      0x0032   100   100   000    Old_age   Always       -       0
194 Temperature_Celsius     0x0022   059   049   000    Old_age   Always       -       41 (Min/Max 0/51)
196 Reallocated_Event_Count 0x0032   100   100   000    Old_age   Always       -       0
197 Bogus_Current_Pend_Sect 0x0032   100   100   000    Old_age   Always       -       0
198 Offline_Uncorrectable   0x0030   100   100   000    Old_age   Offline      -       0
199 UDMA_CRC_Error_Count    0x0032   100   100   000    Old_age   Always       -       4
202 Percent_Lifetime_Remain 0x0030   099   099   001    Old_age   Offline      -       1
206 Write_Error_Rate        0x000e   100   100   000    Old_age   Always       -       0
210 Success_RAIN_Recov_Cnt  0x0032   100   100   000    Old_age   Always       -       0
246 Total_LBAs_Written      0x0032   100   100   000    Old_age   Always       -       8068464723
247 Host_Program_Page_Count 0x0032   100   100   000    Old_age   Always       -       136319482
248 FTL_Program_Page_Count  0x0032   100   100   000    Old_age   Always       -       81387530

root@ubuntu:/usr/src/gsmartcontrol-1.1.3# smartctl --all /dev/sda
smartctl 7.1 2019-12-30 r5022 [x86_64-linux-5.4.0-26-generic] (local build)
Copyright (C) 2002-19, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF INFORMATION SECTION ===
Model Family:     Crucial/Micron MX500 SSDs
Device Model:     CT500MX500SSD1
Serial Number:    2002E2330312
LU WWN Device Id: 5 00a075 1e2330312
Firmware Version: M3CR023
User Capacity:    500,107,862,016 bytes [500 GB]
Sector Sizes:     512 bytes logical, 4096 bytes physical
Rotation Rate:    Solid State Device
Form Factor:      2.5 inches
Device is:        In smartctl database [for details use: -P show]
ATA Version is:   ACS-3 T13/2161-D revision 5
SATA Version is:  SATA 3.3, 6.0 Gb/s (current: 6.0 Gb/s)
Local Time is:    Mon Jul 20 19:57:11 2020 UTC

==> WARNING: This firmware returns bogus raw values in attribute 197

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:  (0x03) Offline data collection activity
                                        is in progress.
                                        Auto Offline Data Collection: Disabled.
Self-test execution status:      ( 249) Self-test routine in progress...
                                        90% of test remaining.
Total time to complete Offline
data collection:                ( 1303) 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:        (  30) minutes.
Conveyance self-test routine
recommended polling time:        (   2) minutes.
SCT capabilities:              (0x0031) 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   100   100   000    Pre-fail  Always       -       0
  5 Reallocate_NAND_Blk_Cnt 0x0032   100   100   010    Old_age   Always       -       0
  9 Power_On_Hours          0x0032   100   100   000    Old_age   Always       -       295
 12 Power_Cycle_Count       0x0032   100   100   000    Old_age   Always       -       20
171 Program_Fail_Count      0x0032   100   100   000    Old_age   Always       -       0
172 Erase_Fail_Count        0x0032   100   100   000    Old_age   Always       -       0
173 Ave_Block-Erase_Count   0x0032   099   099   000    Old_age   Always       -       28
174 Unexpect_Power_Loss_Ct  0x0032   100   100   000    Old_age   Always       -       13
180 Unused_Reserve_NAND_Blk 0x0033   000   000   000    Pre-fail  Always       -       36
183 SATA_Interfac_Downshift 0x0032   100   100   000    Old_age   Always       -       0
184 Error_Correction_Count  0x0032   100   100   000    Old_age   Always       -       0
187 Reported_Uncorrect      0x0032   100   100   000    Old_age   Always       -       0
194 Temperature_Celsius     0x0022   059   049   000    Old_age   Always       -       41 (Min/Max 0/51)
196 Reallocated_Event_Count 0x0032   100   100   000    Old_age   Always       -       0
197 Bogus_Current_Pend_Sect 0x0032   100   100   000    Old_age   Always       -       0
198 Offline_Uncorrectable   0x0030   100   100   000    Old_age   Offline      -       0
199 UDMA_CRC_Error_Count    0x0032   100   100   000    Old_age   Always       -       4
202 Percent_Lifetime_Remain 0x0030   099   099   001    Old_age   Offline      -       1
206 Write_Error_Rate        0x000e   100   100   000    Old_age   Always       -       0
210 Success_RAIN_Recov_Cnt  0x0032   100   100   000    Old_age   Always       -       0
246 Total_LBAs_Written      0x0032   100   100   000    Old_age   Always       -       8068464723
247 Host_Program_Page_Count 0x0032   100   100   000    Old_age   Always       -       136319482
248 FTL_Program_Page_Count  0x0032   100   100   000    Old_age   Always       -       81387535

SMART Error Log Version: 1
Warning: ATA error count 0 inconsistent with error log pointer 1

ATA Error Count: 0
        CR = Command Register [HEX]
        FR = Features Register [HEX]
        SC = Sector Count Register [HEX]
        SN = Sector Number Register [HEX]
        CL = Cylinder Low Register [HEX]
        CH = Cylinder High Register [HEX]
        DH = Device/Head Register [HEX]
        DC = Device Command Register [HEX]
        ER = Error register [HEX]
        ST = Status register [HEX]
Powered_Up_Time is measured from power on, and printed as
DDd+hh:mm:SS.sss where DD=days, hh=hours, mm=minutes,
SS=sec, and sss=millisec. It "wraps" after 49.710 days.

Error 0 occurred at disk power-on lifetime: 0 hours (0 days + 0 hours)
  When the command that caused the error occurred, the device was in an unknown state.

  After command completion occurred, registers were:
  ER ST SC SN CL CH DH
  -- -- -- -- -- -- --
  00 ec 00 00 00 00 00

  Commands leading to the command that caused the error were:
  CR FR SC SN CL CH DH DC   Powered_Up_Time  Command/Feature_Name
  -- -- -- -- -- -- -- --  ----------------  --------------------
  ec 00 00 00 00 00 00 00      00:00:00.000  IDENTIFY DEVICE
  ec 00 00 00 00 00 00 00      00:00:00.000  IDENTIFY DEVICE
  ec 00 00 00 00 00 00 00      00:00:00.000  IDENTIFY DEVICE
  ec 00 00 00 00 00 00 00      00:00:00.000  IDENTIFY DEVICE
  c8 00 00 00 00 00 00 00      00:00:00.000  READ DMA

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  Self_test_in_progress [90% left] (0-65535)
    2        0        0  Not_testing
    3        0        0  Not_testing
    4        0        0  Not_testing
    5        0        0  Not_testing
Selective self-test flags (0x10):
  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.```
0

I fail to see anything which indicates that the "bad" drive is failing at the moment except UDMA_CRC_Error_Count which is a little bit too high. Please try replacing the SSD cable.

  • If it still doesn't help, run the following commands:
sudo cat /dev/sda > /dev/null
echo $?

Should return 0 and there should be no sda related errors or warnings in dmesg.

  • Secondly run
sudo smartctl -t long /dev/sda
# Some 20 minutes or later (you will be told how much it takes)
sudo smartctl -a /dev/sda

You should be seeing something like

Num  Test_Description    Status                  Remaining  LifeTime(hours)  LBA_of_first_error
# 1  Extended offline    Completed without error       00%     1234          -

If it's anything but "Completed without error" probably you should replace the drive ASAP.

Mind that SSD vendors often don't fully support the SMART standard, so the smartctl -t long /dev/sda may not work at all.

  • Lastly if you can temporary remove the drive from active use, reboot into recovery/LiveCD, and run
badblocks -b 4096 -s -n /dev/sda

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