Smart error and how to replace disk properly?

[Mr. Bigglesworth]

I have received a SMART error today when doing a long self-test
The output is this:

Code:

smartctl 6.5 2016-05-07 r4318 [FreeBSD 11.0-STABLE amd64] (local build)
Copyright (C) 2002-16, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF INFORMATION SECTION ===
Model Family:	 Western Digital Red
Device Model:	 WDC WD40EFRX-68WT0N0
Serial Number:	WD-WCC4E0241524
LU WWN Device Id: 5 0014ee 2b3c1622d
Firmware Version: 80.00A80
User Capacity:	4,000,787,030,016 bytes [4.00 TB]
Sector Sizes:	 512 bytes logical, 4096 bytes physical
Rotation Rate:	5400 rpm
Device is:		In smartctl database [for details use: -P show]
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:	Wed Nov  8 14:33:27 2017 CET
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:	  ( 113) The previous self-test completed having
										the read element of the test failed.
Total time to complete Offline
data collection:				(52860) 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:		( 529) minutes.
Conveyance self-test routine
recommended polling time:		(   5) minutes.
SCT capabilities:			  (0x703d) SCT Status supported.
										SCT Error Recovery Control 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	   -	   1
  3 Spin_Up_Time			0x0027   182   177   021	Pre-fail  Always	   -	   7858
  4 Start_Stop_Count		0x0032   091   091   000	Old_age   Always	   -	   9420
  5 Reallocated_Sector_Ct   0x0033   200   200   140	Pre-fail  Always	   -	   0
  7 Seek_Error_Rate		 0x002e   200   200   000	Old_age   Always	   -	   0
  9 Power_On_Hours		  0x0032   067   067   000	Old_age   Always	   -	   24491
10 Spin_Retry_Count		0x0032   100   100   000	Old_age   Always	   -	   0
11 Calibration_Retry_Count 0x0032   100   100   000	Old_age   Always	   -	   0
12 Power_Cycle_Count	   0x0032   100   100   000	Old_age   Always	   -	   143
192 Power-Off_Retract_Count 0x0032   200   200   000	Old_age   Always	   -	   57
193 Load_Cycle_Count		0x0032   189   189   000	Old_age   Always	   -	   34599
194 Temperature_Celsius	 0x0022   112   093   000	Old_age   Always	   -	   40
196 Reallocated_Event_Count 0x0032   200   200   000	Old_age   Always	   -	   0
197 Current_Pending_Sector  0x0032   200   200   000	Old_age   Always	   -	   0
198 Offline_Uncorrectable   0x0030   100   253   000	Old_age   Offline	  -	   0
199 UDMA_CRC_Error_Count	0x0032   200   200   000	Old_age   Always	   -	   437
200 Multi_Zone_Error_Rate   0x0008   200   200   000	Old_age   Offline	  -	   1

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%	 24491		 3025669072

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.

So - I guess things are not working as they should and now I need to replace the disk?
This is what I've come up with by reading other threads on the forum:

1) Power off FreeNAS box
2) Identify disk via serial number
3) Remove old disk and insert new disk
4) Power on FreeNAS
5) ???
6) Woo data is still safe

Could someone tell me how I should proceed when I've powered up FreeNAS again? Will FreeNAS automatically start the rebuild?
Also, could someone tell me what exactly is causing the error?
I can see that it is read failure, but shouldn't it increase the Reallocated_Event_Count?

 

[chris crude]

You might want to look at these steps BEFORE you power off and replace the drive.
http://doc.freenas.org/11/storage.html#replacing-a-failed-drive

 

[Mr. Bigglesworth]

You might want to look at these steps BEFORE you power off and replace the drive.
http://doc.freenas.org/11/storage.html#replacing-a-failed-drive

Thanks - I can see that I was on the wrong track, seems pretty straightforward though.

 

[chris crude]

You were on the right track, you just missed the first step of making sure the disk is OFFLINE before you go through the procedure. I recently replaced 5x2TB with 5x3TB using this method, no issues other than waiting for ZFS pool resilver each time i replaced a disk.

 

[SweetAndLow]

This is the first smart test you have ever run. You should start by configuring reoccurring smart tests. Long tests sound run weekly and short tests should run every couple days.

 

[Mr. Bigglesworth]

This is the first smart test you have ever run. You should start by configuring reoccurring smart tests. Long tests sound run weekly and short tests should run every couple days.

You are correct - This was actually my first scheduled run, I was not aware that it had never been activated.

 

[danb35]

http://doc.freenas.org/11/storage.html#replacing-a-failed-drive

Kind of makes you wonder why they bother writing a manual.

 

[Mr. Bigglesworth]

Hello

I just wanted to say that the resilvering completed without incident and the system is now reporting no errors.

 

[chris crude]

Hello

I just wanted to say that the resilvering completed without incident and the system is now reporting no errors.

Great!
Now that's done hopefully you have time to setup SMART testing on those drives as SweetandLow advised.
http://doc.freenas.org/11/services.html#s-m-a-r-t

 

[Mr. Bigglesworth]

Great!
Now that's done hopefully you have time to setup SMART testing on those drives as SweetandLow advised.
http://doc.freenas.org/11/services.html#s-m-a-r-t

I already did - the error actually came up on the first long DST test that ran on the new schedule, so it was definately not a moment too soon.

 

[chris crude]

Yes i see now, perhaps i should read the entire thread instead of just the posts in which i am quoted.