50% failure rate for Seagate 4TB NAS, is it possible? (ST4000VN000)

[EyeKey]

So less than two years ago I bought 8 Seagate drives. (I purchased them from Amazon in two batches). I run them in raidz2.
I run routinely long smart tests, and one day after a month one disk suddenly had read error, and showed 8 Current_Pending_Sector and Offline_Uncorrectable. Than it was find for a day, and after that it started to show ATA errors and I started to get CRC errors and the Reallocated_Sector_Ct raised (to the hundreds). So I RMA'd it, and everything was fine for the next year and half.
Suddenly two months ago, another disk had the 8 Current_Pending_Sector and Offline_Uncorrectable. Before I had the chance to deal with it (one day later), my mother board died (my C2750D4I, but that is another story).
So I finally got the motherboard two weeks ago, I ran badblocks on that drive, and everything looked fine, so I resilvered it and didn't RMA it (I have redundancy of 2 so I wasn't too worried).
But... yesterday I got the 8 sectors error on two more disks! So the first thing that I did to run scrub to verify that my data is fine, but guess what? I got a lot of CRC errors, not on those two disks, but on the disk that had it two months ago (and the relocated sectors count raised). So now I am in a situation that I have 3 bad disks in raidz2 (the nightmare). I rushed to the store to buy another disk (WD this time), and I am resilvering it into the array right now. (It is going to finish soon and there isn't any error). After that I will have the minimal number of 'ok' disks in my raid for now.

So I am going to RMA that disk ASAP (it has ATA errors now too). And I am pretty that those two other disks are time bombs too so I will RMA them too one by one (one of them already had ATA errors, but the bad sectors hasn't start to raise yet).

Now.... How it is possible? Can it be something wrong with my server? 3 disks die almost simultaneously after 11K hours?

 

[EyeKey]

Here are the smartctls: (The temperatures are bit higher than usual because of the resilvering)

Code:

smartctl 6.5 2016-05-07 r4318 [FreeBSD 11.1-STABLE amd64] (local build)
Copyright (C) 2002-16, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF INFORMATION SECTION ===
Model Family:	 Seagate NAS HDD
Device Model:	 ST4000VN000-2AH166
Serial Number:	XXXXXXXX
LU WWN Device Id: 5 000c50 09ced5e55
Firmware Version: SC60
User Capacity:	4,000,787,030,016 bytes [4.00 TB]
Sector Sizes:	 512 bytes logical, 4096 bytes physical
Rotation Rate:	5980 rpm
Form Factor:	  3.5 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 3.1, 6.0 Gb/s (current: 6.0 Gb/s)
Local Time is:	Mon Jun 11 16:46:36 2018 IDT
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:				(  591) 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:		( 660) 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   100   053   044	Pre-fail  Always	   -	   0
  3 Spin_Up_Time			0x0003   093   093   000	Pre-fail  Always	   -	   0
  4 Start_Stop_Count		0x0032   100   100   020	Old_age   Always	   -	   35
  5 Reallocated_Sector_Ct   0x0033   100   100   010	Pre-fail  Always	   -	   384
  7 Seek_Error_Rate		 0x000f   085   060   045	Pre-fail  Always	   -	   289994735
  9 Power_On_Hours		  0x0032   087   087   000	Old_age   Always	   -	   11935 (129 150 0)
 10 Spin_Retry_Count		0x0013   100   100   097	Pre-fail  Always	   -	   0
 12 Power_Cycle_Count	   0x0032   100   100   020	Old_age   Always	   -	   39
184 End-to-End_Error		0x0032   100   100   099	Old_age   Always	   -	   0
187 Reported_Uncorrect	  0x0032   063   063   000	Old_age   Always	   -	   37
188 Command_Timeout		 0x0032   100   100   000	Old_age   Always	   -	   0
189 High_Fly_Writes		 0x003a   100   100   000	Old_age   Always	   -	   0
190 Airflow_Temperature_Cel 0x0022   054   047   040	Old_age   Always	   -	   46 (Min/Max 37/47)
191 G-Sense_Error_Rate	  0x0032   100   100   000	Old_age   Always	   -	   0
192 Power-Off_Retract_Count 0x0032   100   100   000	Old_age   Always	   -	   34
193 Load_Cycle_Count		0x0032   100   100   000	Old_age   Always	   -	   116
194 Temperature_Celsius	 0x0022   046   053   000	Old_age   Always	   -	   46 (0 21 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   253   000	Old_age   Offline	  -	   11932 (133 34 0)
241 Total_LBAs_Written	  0x0000   100   253   000	Old_age   Offline	  -	   29679936742
242 Total_LBAs_Read		 0x0000   100   253   000	Old_age   Offline	  -	   142036008252

SMART Error Log Version: 1
ATA Error Count: 37 (device log contains only the most recent five errors)
		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 37 occurred at disk power-on lifetime: 11927 hours (496 days + 23 hours)
  When the command that caused the error occurred, the device was active or idle.

  After command completion occurred, registers were:
  ER ST SC SN CL CH DH
  -- -- -- -- -- -- --
  40 51 00 ff ff ff 0f  Error: UNC at LBA = 0x0fffffff = 268435455

  Commands leading to the command that caused the error were:
  CR FR SC SN CL CH DH DC   Powered_Up_Time  Command/Feature_Name
  -- -- -- -- -- -- -- --  ----------------  --------------------
  60 00 00 ff ff ff 4f 00   9d+13:31:24.093  READ FPDMA QUEUED
  60 00 00 ff ff ff 4f 00   9d+13:31:24.093  READ FPDMA QUEUED
  60 00 00 ff ff ff 4f 00   9d+13:31:24.093  READ FPDMA QUEUED
  60 00 00 ff ff ff 4f 00   9d+13:31:24.093  READ FPDMA QUEUED
  60 00 00 ff ff ff 4f 00   9d+13:31:24.093  READ FPDMA QUEUED

Error 36 occurred at disk power-on lifetime: 11927 hours (496 days + 23 hours)
  When the command that caused the error occurred, the device was active or idle.

  After command completion occurred, registers were:
  ER ST SC SN CL CH DH
  -- -- -- -- -- -- --
  40 51 00 ff ff ff 0f  Error: UNC at LBA = 0x0fffffff = 268435455

  Commands leading to the command that caused the error were:
  CR FR SC SN CL CH DH DC   Powered_Up_Time  Command/Feature_Name
  -- -- -- -- -- -- -- --  ----------------  --------------------
  60 00 00 ff ff ff 4f 00   9d+13:31:20.693  READ FPDMA QUEUED
  60 00 00 ff ff ff 4f 00   9d+13:31:20.693  READ FPDMA QUEUED
  60 00 00 ff ff ff 4f 00   9d+13:31:20.693  READ FPDMA QUEUED
  60 00 00 ff ff ff 4f 00   9d+13:31:20.693  READ FPDMA QUEUED
  60 00 00 ff ff ff 4f 00   9d+13:31:20.693  READ FPDMA QUEUED

Error 35 occurred at disk power-on lifetime: 11927 hours (496 days + 23 hours)
  When the command that caused the error occurred, the device was active or idle.

  After command completion occurred, registers were:
  ER ST SC SN CL CH DH
  -- -- -- -- -- -- --
  40 51 00 ff ff ff 0f  Error: UNC at LBA = 0x0fffffff = 268435455

  Commands leading to the command that caused the error were:
  CR FR SC SN CL CH DH DC   Powered_Up_Time  Command/Feature_Name
  -- -- -- -- -- -- -- --  ----------------  --------------------
  60 00 00 ff ff ff 4f 00   9d+13:31:17.522  READ FPDMA QUEUED
  60 00 00 ff ff ff 4f 00   9d+13:31:17.522  READ FPDMA QUEUED
  60 00 00 ff ff ff 4f 00   9d+13:31:17.522  READ FPDMA QUEUED
  60 00 00 ff ff ff 4f 00   9d+13:31:17.522  READ FPDMA QUEUED
  60 00 00 ff ff ff 4f 00   9d+13:31:17.522  READ FPDMA QUEUED

Error 34 occurred at disk power-on lifetime: 11927 hours (496 days + 23 hours)
  When the command that caused the error occurred, the device was active or idle.

  After command completion occurred, registers were:
  ER ST SC SN CL CH DH
  -- -- -- -- -- -- --
  40 51 00 ff ff ff 0f  Error: UNC at LBA = 0x0fffffff = 268435455

  Commands leading to the command that caused the error were:
  CR FR SC SN CL CH DH DC   Powered_Up_Time  Command/Feature_Name
  -- -- -- -- -- -- -- --  ----------------  --------------------
  60 00 00 ff ff ff 4f 00   9d+13:31:14.345  READ FPDMA QUEUED
  60 00 00 ff ff ff 4f 00   9d+13:31:14.345  READ FPDMA QUEUED
  60 00 00 ff ff ff 4f 00   9d+13:31:14.345  READ FPDMA QUEUED
  60 00 00 ff ff ff 4f 00   9d+13:31:14.345  READ FPDMA QUEUED
  60 00 00 ff ff ff 4f 00   9d+13:31:14.345  READ FPDMA QUEUED

Error 33 occurred at disk power-on lifetime: 11927 hours (496 days + 23 hours)
  When the command that caused the error occurred, the device was active or idle.

  After command completion occurred, registers were:
  ER ST SC SN CL CH DH
  -- -- -- -- -- -- --
  40 51 00 ff ff ff 0f  Error: UNC at LBA = 0x0fffffff = 268435455

  Commands leading to the command that caused the error were:
  CR FR SC SN CL CH DH DC   Powered_Up_Time  Command/Feature_Name
  -- -- -- -- -- -- -- --  ----------------  --------------------
  60 00 00 ff ff ff 4f 00   9d+13:31:11.227  READ FPDMA QUEUED
  60 00 00 ff ff ff 4f 00   9d+13:31:11.227  READ FPDMA QUEUED
  60 00 00 ff ff ff 4f 00   9d+13:31:11.227  READ FPDMA QUEUED
  60 00 00 ff ff ff 4f 00   9d+13:31:11.226  READ FPDMA QUEUED
  2f 00 01 10 00 00 00 00   9d+13:31:11.163  READ LOG EXT

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%	 11747		 -
# 2  Short offline	   Completed without error	   00%	 11686		 -
# 3  Extended offline	Completed: read failure	   10%	 11685		 -
# 4  Extended offline	Completed without error	   00%	 11673		 -
# 5  Short offline	   Completed without error	   00%	 11518		 -
# 6  Extended offline	Completed without error	   00%	 11358		 -
# 7  Short offline	   Completed without error	   00%	 11182		 -
# 8  Short offline	   Completed without error	   00%	 11014		 -
# 9  Extended offline	Completed without error	   00%	 11002		 -
#10  Short offline	   Completed without error	   00%	 10846		 -
#11  Extended offline	Completed without error	   00%	 10666		 -
#12  Short offline	   Completed without error	   00%	 10606		 -
#13  Short offline	   Completed without error	   00%	 10438		 -
#14  Extended offline	Completed without error	   00%	 10329		 -
#15  Short offline	   Completed without error	   00%	 10102		 -
#16  Short offline	   Completed without error	   00%	  9862		 -
#17  Extended offline	Completed without error	   00%	  9825		 -
#18  Short offline	   Completed without error	   00%	  9694		 -
#19  Short offline	   Completed without error	   00%	  9526		 -
#20  Extended offline	Completed without error	   00%	  9489		 -
#21  Short offline	   Completed without error	   00%	  9358		 -
1 of 1 failed self-tests are outdated by newer successful extended offline self-test # 1

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.

Code:

martctl 6.5 2016-05-07 r4318 [FreeBSD 11.1-STABLE amd64] (local build)
Copyright (C) 2002-16, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF INFORMATION SECTION ===
Model Family:	 Seagate NAS HDD
Device Model:	 ST4000VN000-2AH166
Serial Number:	XXXXXXX
LU WWN Device Id: 5 000c50 09289b35a
Firmware Version: SC60
User Capacity:	4,000,787,030,016 bytes [4.00 TB]
Sector Sizes:	 512 bytes logical, 4096 bytes physical
Rotation Rate:	5980 rpm
Form Factor:	  3.5 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 3.1, 6.0 Gb/s (current: 6.0 Gb/s)
Local Time is:	Mon Jun 11 16:48:54 2018 IDT
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:				(  591) 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:		( 625) 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   083   064   044	Pre-fail  Always	   -	   209961800
  3 Spin_Up_Time			0x0003   094   093   000	Pre-fail  Always	   -	   0
  4 Start_Stop_Count		0x0032   100   100   020	Old_age   Always	   -	   42
  5 Reallocated_Sector_Ct   0x0033   100   100   010	Pre-fail  Always	   -	   0
  7 Seek_Error_Rate		 0x000f   084   060   045	Pre-fail  Always	   -	   235205390
  9 Power_On_Hours		  0x0032   087   087   000	Old_age   Always	   -	   11935 (4 193 0)
 10 Spin_Retry_Count		0x0013   100   100   097	Pre-fail  Always	   -	   0
 12 Power_Cycle_Count	   0x0032   100   100   020	Old_age   Always	   -	   42
184 End-to-End_Error		0x0032   100   100   099	Old_age   Always	   -	   0
187 Reported_Uncorrect	  0x0032   090   090   000	Old_age   Always	   -	   10
188 Command_Timeout		 0x0032   100   100   000	Old_age   Always	   -	   0
189 High_Fly_Writes		 0x003a   100   100   000	Old_age   Always	   -	   0
190 Airflow_Temperature_Cel 0x0022   048   046   040	Old_age   Always	   -	   52 (Min/Max 41/53)
191 G-Sense_Error_Rate	  0x0032   100   100   000	Old_age   Always	   -	   0
192 Power-Off_Retract_Count 0x0032   100   100   000	Old_age   Always	   -	   35
193 Load_Cycle_Count		0x0032   100   100   000	Old_age   Always	   -	   139
194 Temperature_Celsius	 0x0022   052   054   000	Old_age   Always	   -	   52 (0 20 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   253   000	Old_age   Offline	  -	   11930 (146 59 0)
241 Total_LBAs_Written	  0x0000   100   253   000	Old_age   Offline	  -	   9934489313
242 Total_LBAs_Read		 0x0000   100   253   000	Old_age   Offline	  -	   133986028148

SMART Error Log Version: 1
ATA Error Count: 10 (device log contains only the most recent five errors)
		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 10 occurred at disk power-on lifetime: 11927 hours (496 days + 23 hours)
  When the command that caused the error occurred, the device was active or idle.

  After command completion occurred, registers were:
  ER ST SC SN CL CH DH
  -- -- -- -- -- -- --
  40 51 00 ff ff ff 0f  Error: UNC at LBA = 0x0fffffff = 268435455

  Commands leading to the command that caused the error were:
  CR FR SC SN CL CH DH DC   Powered_Up_Time  Command/Feature_Name
  -- -- -- -- -- -- -- --  ----------------  --------------------
  25 00 00 ff ff ff 4f 00   9d+13:28:31.741  READ DMA EXT
  25 00 00 ff ff ff 4f 00   9d+13:28:28.992  READ DMA EXT
  25 00 00 ff ff ff 4f 00   9d+13:28:26.242  READ DMA EXT
  25 00 00 ff ff ff 4f 00   9d+13:28:23.435  READ DMA EXT
  25 00 00 ff ff ff 4f 00   9d+13:28:20.566  READ DMA EXT

Error 9 occurred at disk power-on lifetime: 11927 hours (496 days + 23 hours)
  When the command that caused the error occurred, the device was active or idle.

  After command completion occurred, registers were:
  ER ST SC SN CL CH DH
  -- -- -- -- -- -- --
  40 51 00 ff ff ff 0f  Error: UNC at LBA = 0x0fffffff = 268435455

  Commands leading to the command that caused the error were:
  CR FR SC SN CL CH DH DC   Powered_Up_Time  Command/Feature_Name
  -- -- -- -- -- -- -- --  ----------------  --------------------
  25 00 00 ff ff ff 4f 00   9d+13:28:28.992  READ DMA EXT
  25 00 00 ff ff ff 4f 00   9d+13:28:26.242  READ DMA EXT
  25 00 00 ff ff ff 4f 00   9d+13:28:23.435  READ DMA EXT
  25 00 00 ff ff ff 4f 00   9d+13:28:20.566  READ DMA EXT
  60 00 d0 ff ff ff 4f 00   9d+13:28:20.537  READ FPDMA QUEUED

Error 8 occurred at disk power-on lifetime: 11927 hours (496 days + 23 hours)
  When the command that caused the error occurred, the device was active or idle.

  After command completion occurred, registers were:
  ER ST SC SN CL CH DH
  -- -- -- -- -- -- --
  40 51 00 ff ff ff 0f  Error: UNC at LBA = 0x0fffffff = 268435455

  Commands leading to the command that caused the error were:
  CR FR SC SN CL CH DH DC   Powered_Up_Time  Command/Feature_Name
  -- -- -- -- -- -- -- --  ----------------  --------------------
  25 00 00 ff ff ff 4f 00   9d+13:28:26.242  READ DMA EXT
  25 00 00 ff ff ff 4f 00   9d+13:28:23.435  READ DMA EXT
  25 00 00 ff ff ff 4f 00   9d+13:28:20.566  READ DMA EXT
  60 00 d0 ff ff ff 4f 00   9d+13:28:20.537  READ FPDMA QUEUED
  60 00 00 ff ff ff 4f 00   9d+13:28:20.537  READ FPDMA QUEUED

Error 7 occurred at disk power-on lifetime: 11927 hours (496 days + 23 hours)
  When the command that caused the error occurred, the device was active or idle.

  After command completion occurred, registers were:
  ER ST SC SN CL CH DH
  -- -- -- -- -- -- --
  40 51 00 ff ff ff 0f  Error: UNC at LBA = 0x0fffffff = 268435455

  Commands leading to the command that caused the error were:
  CR FR SC SN CL CH DH DC   Powered_Up_Time  Command/Feature_Name
  -- -- -- -- -- -- -- --  ----------------  --------------------
  25 00 00 ff ff ff 4f 00   9d+13:28:23.435  READ DMA EXT
  25 00 00 ff ff ff 4f 00   9d+13:28:20.566  READ DMA EXT
  60 00 d0 ff ff ff 4f 00   9d+13:28:20.537  READ FPDMA QUEUED
  60 00 00 ff ff ff 4f 00   9d+13:28:20.537  READ FPDMA QUEUED
  60 00 98 ff ff ff 4f 00   9d+13:28:20.537  READ FPDMA QUEUED

Error 6 occurred at disk power-on lifetime: 11927 hours (496 days + 23 hours)
  When the command that caused the error occurred, the device was active or idle.

  After command completion occurred, registers were:
  ER ST SC SN CL CH DH
  -- -- -- -- -- -- --
  40 51 00 ff ff ff 0f  Error: UNC at LBA = 0x0fffffff = 268435455

  Commands leading to the command that caused the error were:
  CR FR SC SN CL CH DH DC   Powered_Up_Time  Command/Feature_Name
  -- -- -- -- -- -- -- --  ----------------  --------------------
  25 00 00 ff ff ff 4f 00   9d+13:28:20.566  READ DMA EXT
  60 00 d0 ff ff ff 4f 00   9d+13:28:20.537  READ FPDMA QUEUED
  60 00 00 ff ff ff 4f 00   9d+13:28:20.537  READ FPDMA QUEUED
  60 00 98 ff ff ff 4f 00   9d+13:28:20.537  READ FPDMA QUEUED
  60 00 00 ff ff ff 4f 00   9d+13:28:20.537  READ FPDMA QUEUED

SMART Self-test log structure revision number 1
Num  Test_Description	Status				  Remaining  LifeTime(hours)  LBA_of_first_error
# 1  Extended offline	Completed: read failure	   10%	 11905		 -
# 2  Short offline	   Completed without error	   00%	 11774		 -
# 3  Short offline	   Completed without error	   00%	 11686		 -
# 4  Extended offline	Completed without error	   00%	 11673		 -
# 5  Short offline	   Completed without error	   00%	 11518		 -
# 6  Short offline	   Completed without error	   00%	 11350		 -
# 7  Extended offline	Completed without error	   00%	 11339		 -
# 8  Short offline	   Completed without error	   00%	 11182		 -
# 9  Short offline	   Completed without error	   00%	 11014		 -
#10  Extended offline	Completed without error	   00%	 11001		 -
#11  Short offline	   Completed without error	   00%	 10846		 -
#12  Extended offline	Completed without error	   00%	 10665		 -
#13  Short offline	   Completed without error	   00%	 10606		 -
#14  Short offline	   Completed without error	   00%	 10438		 -
#15  Extended offline	Completed without error	   00%	 10329		 -
#16  Short offline	   Completed without error	   00%	 10102		 -
#17  Short offline	   Completed without error	   00%	  9862		 -
#18  Extended offline	Completed without error	   00%	  9825		 -
#19  Short offline	   Completed without error	   00%	  9694		 -
#20  Short offline	   Completed without error	   00%	  9526		 -
#21  Extended offline	Completed without error	   00%	  9489		 -

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.

Code:

smartctl 6.5 2016-05-07 r4318 [FreeBSD 11.1-STABLE amd64] (local build)
Copyright (C) 2002-16, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF INFORMATION SECTION ===
Model Family:	 Seagate NAS HDD
Device Model:	 ST4000VN000-2AH166
Serial Number:	XXXXXXX
LU WWN Device Id: 5 000c50 09289623f
Firmware Version: SC60
User Capacity:	4,000,787,030,016 bytes [4.00 TB]
Sector Sizes:	 512 bytes logical, 4096 bytes physical
Rotation Rate:	5980 rpm
Form Factor:	  3.5 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 3.1, 6.0 Gb/s (current: 6.0 Gb/s)
Local Time is:	Mon Jun 11 16:49:29 2018 IDT
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:				(  591) 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:		( 633) 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   084   064   044	Pre-fail  Always	   -	   230261112
  3 Spin_Up_Time			0x0003   094   093   000	Pre-fail  Always	   -	   0
  4 Start_Stop_Count		0x0032   100   100   020	Old_age   Always	   -	   43
  5 Reallocated_Sector_Ct   0x0033   100   100   010	Pre-fail  Always	   -	   0
  7 Seek_Error_Rate		 0x000f   084   060   045	Pre-fail  Always	   -	   276559940
  9 Power_On_Hours		  0x0032   087   087   000	Old_age   Always	   -	   11935 (81 185 0)
 10 Spin_Retry_Count		0x0013   100   100   097	Pre-fail  Always	   -	   0
 12 Power_Cycle_Count	   0x0032   100   100   020	Old_age   Always	   -	   43
184 End-to-End_Error		0x0032   100   100   099	Old_age   Always	   -	   0
187 Reported_Uncorrect	  0x0032   100   100   000	Old_age   Always	   -	   0
188 Command_Timeout		 0x0032   100   100   000	Old_age   Always	   -	   0
189 High_Fly_Writes		 0x003a   100   100   000	Old_age   Always	   -	   0
190 Airflow_Temperature_Cel 0x0022   049   047   040	Old_age   Always	   -	   51 (Min/Max 40/52)
191 G-Sense_Error_Rate	  0x0032   100   100   000	Old_age   Always	   -	   0
192 Power-Off_Retract_Count 0x0032   100   100   000	Old_age   Always	   -	   34
193 Load_Cycle_Count		0x0032   100   100   000	Old_age   Always	   -	   120
194 Temperature_Celsius	 0x0022   051   053   000	Old_age   Always	   -	   51 (0 20 0 0 0)
197 Current_Pending_Sector  0x0012   100   100   000	Old_age   Always	   -	   8
198 Offline_Uncorrectable   0x0010   100   100   000	Old_age   Offline	  -	   8
199 UDMA_CRC_Error_Count	0x003e   200   200   000	Old_age   Always	   -	   0
240 Head_Flying_Hours	   0x0000   100   253   000	Old_age   Offline	  -	   11932 (135 210 0)
241 Total_LBAs_Written	  0x0000   100   253   000	Old_age   Offline	  -	   10217560682
242 Total_LBAs_Read		 0x0000   100   253   000	Old_age   Offline	  -	   134432390229

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: read failure	   10%	 11905		 -
# 2  Short offline	   Completed without error	   00%	 11774		 -
# 3  Short offline	   Completed without error	   00%	 11686		 -
# 4  Extended offline	Completed without error	   00%	 11673		 -
# 5  Short offline	   Completed without error	   00%	 11518		 -
# 6  Extended offline	Completed without error	   00%	 11358		 -
# 7  Short offline	   Completed without error	   00%	 11182		 -
# 8  Short offline	   Completed without error	   00%	 11014		 -
# 9  Extended offline	Completed without error	   00%	 11002		 -
#10  Short offline	   Completed without error	   00%	 10846		 -
#11  Extended offline	Completed without error	   00%	 10666		 -
#12  Short offline	   Completed without error	   00%	 10606		 -
#13  Short offline	   Completed without error	   00%	 10438		 -
#14  Extended offline	Completed without error	   00%	 10329		 -
#15  Short offline	   Completed without error	   00%	 10102		 -
#16  Short offline	   Completed without error	   00%	  9862		 -
#17  Extended offline	Completed without error	   00%	  9825		 -
#18  Short offline	   Completed without error	   00%	  9694		 -
#19  Short offline	   Completed without error	   00%	  9526		 -
#20  Extended offline	Completed without error	   00%	  9489		 -
#21  Short offline	   Completed without error	   00%	  9358		 -

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.

 

[Inxsible]

Have you considered the fact that it could be the controller or a bad cable? How are the drives connected? SATA cable or on a backplane with SAS connectors?

 

[EyeKey]

Have you considered the fact that it could be the controller or a bad cable? How are the drives connected? SATA cable or on a backplane with SAS connectors?

Can a bad cable/controller cause bad sectors/relocated sectors? I mean I understand that it can cause the ATA errors, but can it causes read errors too? (And in all of those cases the ATA errors showed up only after the uncorrectable sectors showed up first)
The hard-drives are in hot-swappable cases inside SilverStone RS380B case, so it is connected to its SATA panel.
The SATA cables are connected to the SATA controllers that are on the C2750D4I (I am pretty sure that one of the failing disks is connected to a different controller than the other two, is there a command that I can check with it for sure?)
Anyway everything was fine for an year and a half (except for the hard drive that 'died' after one month, I just replaced it in the hot swappable case and the replacement hard disk didn't have any issue since then, so I didn't even reconnect the cable).
(And when I reassembled the server after I switched the motherboard, I connected everything again, and not in the same order, and still the hard drive that showed bad signs a day before the motherboard died (aka the 8-sectors error), suddenly had a lot of bad sectors yesterday and ATA errors)

Can it be a bad disks batch?

 

[Inxsible]

the hard drive that showed bad signs a day before the motherboard died (aka the 8-sectors error), suddenly had a lot of bad sectors yesterday and ATA errors)

It could also have been the dying motherboard that didn't wanna go down without taking a few things along with it.

 

[EyeKey]

It could also have been the dying motherboard that didn't wanna go down without taking a few things along with it.

I don't think so. The motherboard probably died because of the BMC flash issue that affect pretty much almost all of the old C2750D4I boards, the IPMI still worked for example. I didn't see any C2750D4I owner that reported something like that because of the death of his motherboard. And two of the disks started to show signs only with the new motherboard. (And one disk showed the exact same signs only a month after I bought it)

 

[Inxsible]

Point is, there are too many variables to pin-point what the exact cause is.

1. They could have been just bad disks
2. your motherboard dying
3. Bad controller
4. Bad cables.
5. The wrath of God !

You asked what could be wrong with your server and I gave you possible explanations.

 

[EyeKey]

Thanks for that. I just added more info for why it is less reasonable. (mainly because of the increasing number of bad sectors)
Is there any Seagate 4TB owner that had the same issue?

 

[Johnnie Black]

I would guess bad luck or a lot of vibrations in your server, though you're using NAS drives with some vibration tolerance, too much can still be a problem.

 

[Bidule0hm]

The problem is the temp, 50+ °C is not ok for drives, you should be under 40 °C. Improve the cooling and most likely you'll not have dying drives anymore.

 

[EyeKey]

I would guess bad luck or a lot of vibrations in your server, though you're using NAS drives with some vibration tolerance, too much can still be a problem.

Hmm it may be something like that. I don't think that I have a special amount of vibrations, it is just 8 disks in DS380 (that is on a table), and the vibrations are from the hard drives themselves. Does it matter if the server is standing up or on its side? (Right now it is standing up)

The problem is the temp, 50+ °C is not ok for drives, you should be under 40 °C. Improve the cooling and most likely you'll not have dying drives any more.

As I said, it is because of the resilvering. 98% of the time it is under 50. (Usually around 40-45). Yea it isn't low but it isn't very high too, it isn't a temperature that should cause a lot of failures in a hard drives that are rated up to 60C.

 

[Johnnie Black]

Hmm it may be something like that. I don't think that I have a special amount of vibrations, it is just 8 disks in DS380 (that is on a table), and the vibrations are from the hard drives themselves. Does it matter if the server is standing up or on its side? (Right now it is standing up)

I don't know that case but for 8 disks you'd want something with rubber grommets or similar to minimize vibrations, horizontal or vertical should't make much of a difference.

 

[Bidule0hm]

As I said, it is because of the resilvering. 98% of the time it is under 50. (Usually around 40-45). Yea it isn't low but it isn't very high too, it isn't a temperature that should cause a lot of failures in a hard drives that are rated up to 60C.

Actually it is, look at the Google paper, over 40 °C the failure rate skyrocket and over 50 °C we often see immediate problems.

 

[eldo]

EyeKey,

Slightly off topic, but I see you're running the C2750D4I the same as I am.
These boards have 6 intel ports and 6 marvell ports I believe.

How has your system been running using the marvell ports? besides these 4 drive failures which at least one of would be on the intel ports.

 

[Chris Moore]

So I RMA'd it, and everything was fine for the next year and half.

If you went a year and a half with no drive faults, you did good.

Suddenly two months ago, another disk had the 8 Current_Pending_Sector and Offline_Uncorrectable.

Two drive faults in two years isn't so bad. I have a server at work that I had to replace 4 drives in the first six months, but it has been a year now with no faults.

Before I had the chance to deal with it (one day later), my mother board died (my C2750D4I, but that is another story).
So I finally got the motherboard two weeks ago, I ran badblocks on that drive, and everything looked fine, so I resilvered it and didn't RMA it (I have redundancy of 2 so I wasn't too worried).

Bad idea. When a drive has reallocated sectors, that indicates a physical (mechanical) fault with the drive and it will only continue to grow over time. These drives could have been damaged in handling before you received them or they may have had minor manufacturing flaws. It is best to replace a faulted drive, especially when it is in warranty. Don't live with it and wait for it to get worse.

But... yesterday I got the 8 sectors error on two more disks!

That is why. You never know when an error will pop, so you should always have a couple of tested spares on hand. I keep two spares, of each drive size, on the shelf all the time.

but guess what? I got a lot of CRC errors, not on those two disks, but on the disk that had it two months ago (and the relocated sectors count raised).

That is why you should have replaced it when it first gave you errors. Never wait to see if it gets worse because it won't get better. It is a machine, it can't heal on it's own.

I rushed to the store to buy another disk (WD this time),

If you must, but there is nothing wrong with Seagate. Just do the RMA shuffle and get those disks replaced under warranty.

Now.... How it is possible? Can it be something wrong with my server? 3 disks die almost simultaneously after 11K hours?

It could have been a bad run of disks. Sometimes happens. What kind of chassis are they mounted in? What kind of environment?
The airflow temp that the drives are reporting 47°C, 52°C, and 51°C are all quite hot, by my standards. I like to keep them in the 30s. That can be a certain cause of early death in a hard drive.

Can a bad cable/controller cause bad sectors/relocated sectors?

No, but it can cause CRC and ATA errors. What kind of hardware are you using? As many details as you can.

Anyway everything was fine for an year and a half (except for the hard drive that 'died' after one month, I just replaced it in the hot swappable case and the replacement hard disk didn't have any issue since then, so I didn't even reconnect the cable).

How ?? What are you saying? Did you not connect the replacement drive?

As I said, it is because of the resilvering. 98% of the time it is under 50. (Usually around 40-45). Yea it isn't low but it isn't very high too, it isn't a temperature that should cause a lot of failures in a hard drives that are rated up to 60C.

Just because it is rated to a MAX of 60°C, doesn't make it alright to run it that hot. Get some better airflow over those drives to keep them cool all the time. You should be able to run them hard and never break 50°C.

You should probably buy a spare or two to have handy:
https://www.techpartz.com/seagate-s...7AmcwWeSL0oKK1hQbXQ-XPnsmlff0GGRoCmkoQAvD_BwE

Then, once you have got all the Seagates replaced, you can put that WD on eBay and get rid of it.

 

[adrianwi]

My FreeNAS box has been up and running for almost 3 years and has 9 Seagate 4TB drives. In that time I’ve RMA’d 3 of them so my rate is 33%.

 

[colmconn]

That case is a PITA to keep drives cool in. I've got the same MB as you and 6 3TB WD Reds and one 4TB Seagate drive in mine. With the case in its stock configuration (filter grill over side fans my drives easily hit 50C just while idling. I let that go on for one night only. The easiest and most immediate way to get airflow over your drives is to open the door of the case and leave it open. The exhaust fan will then draw air over the drives and you should see your drive temp drop fairly quickly. That, at least, was my experience.

What I ultimately ended up doing was 3D printing a pair of baffles to block the gap between the side fans and the drive cage so that the air had to flow over the drives rather than follow the line of least resistance and go through the gap beside the drive cage. I also used duck tape to ensure that there were no gaps between the baffles and at the base of the case below the baffles that recalcitrant air could flow through rather than over the drives. That reduced the amount of airflow over the passively cooled CPU so I ended up 3D printing a cowl to attach to the heat sink and attaching a fan to that to increase airflow. I also removed the filter over the side fans and replaced it with a pair of typical grills to further increase airflow. Since I've done all this my drive temps have stayed in the 30Cs and the CPU around 35-40C at idle rising to about 50C under load.

For the design files for the baffles and CPU cowl read posts #82 and #85 at https://forums.freenas.org/index.php?threads/asrock-rack-c2750d4i-cpu-temperature-issue.41528/page-5

If you don't have access to a 3D printer there are plenty of places online that will happily print them for you, for a fee, of course.