Do I need to replace this drive urgently?

[surfrock66]

I am running FreeNAS 11.1 and have a RaidZ2 volume with 6-3TB drives. Currently, I have the following critical alerts:

• CRITICAL: Aug. 5, 2018, 6:43 p.m. - Device: /dev/ada4, 3 Currently unreadable (pending) sectors
• CRITICAL: Aug. 6, 2018, 1:39 p.m. - Device: /dev/ada4, 3 Offline uncorrectable sectors

When I look at the status of my disks, all say Healthy. The pool is healthy, and my scrubs appear clean. I have another disk here I could swap in, but I'm wondering if I really need to. I'm seeing that this is a SMART error which is usually an early warning for a failing drive, but since it's offline sectors there's cases that the drive will chug along indefinitely in this state without any reduction in performance. Given the RaidZ2 and scrubs, there's very little risk of data loss (plus this is all backed up offsite). How serious should I treat this alert?

Here's the output of zpool status:


[root@sr66-nas ~]# zpool status
pool: freenas-boot
state: ONLINE
scan: scrub repaired 0 in 0 days 00:02:33 with 0 errors on Wed Aug 8 03:47:34 2018
config:

NAME STATE READ WRITE CKSUM
freenas-boot ONLINE 0 0 0
da0p2 ONLINE 0 0 0

errors: No known data errors

pool: sr66-nas-v01
state: ONLINE
scan: resilvered 1.02T in 0 days 04:36:50 with 0 errors on Tue Jul 10 01:29:33 2018
config:

NAME STATE READ WRITE CKSUM
sr66-nas-v01 ONLINE 0 0 0
raidz2-0 ONLINE 0 0 0
gptid/ae4ba3a0-6c50-11e4-86ab-b8975a5c2ef9 ONLINE 0 0 0
gptid/af31e1af-6c50-11e4-86ab-b8975a5c2ef9 ONLINE 0 0 0
gptid/8e9d48ba-83f4-11e8-8495-b8975a5c2ef9 ONLINE 0 0 0
gptid/b11333ee-6c50-11e4-86ab-b8975a5c2ef9 ONLINE 0 0 0
gptid/b1f4a24f-6c50-11e4-86ab-b8975a5c2ef9 ONLINE 0 0 0
gptid/b2d5879b-6c50-11e4-86ab-b8975a5c2ef9 ONLINE 0 0 0

errors: No known data errors


 

[Chris Moore]

I replace a drive when it starts to show bad sectors because I want to keep my pool healthy. If you wait until the drive becomes degraded to the point that the pool becomes unhealthy, then you've created a problem for yourself that you could have easily avoided.

Sent from my SAMSUNG-SGH-I537 using Tapatalk

 

[anmnz]

How serious should I treat this alert?

Personally I'd take @Chris Moore's approach and replace it. But IMO a reasonable compromise would be to keep an eye on the drive, and replace it immediately if the number of bad sectors starts to increase further.

Then again, what would you be trying to save by not replacing the drive? What is the purpose of that other disk you say you could swap in, if not to be swapped in when a problem like this is reported?

 

[surfrock66]

Personally I'd take @Chris Moore's approach and replace it. But IMO a reasonable compromise would be to keep an eye on the drive, and replace it immediately if the number of bad sectors starts to increase further.

Then again, what would you be trying to save by not replacing the drive? What is the purpose of that other disk you say you could swap in, if not to be swapped in when a problem like this is reported?

Nothing really; seeing that the pool was healthy I thought it was just an overly concerned warning and not a real critical issue. The last disk failure was striking and the pool showed as degraded, so I was a bit confused by this one.

 

[danb35]

I thought it was just an overly concerned warning and not a real critical issue.

Bad sectors should be taken seriously, but if it's only a few, and the rest of the SMART data looks good, you're probably OK to just monitor rather than replace immediately. What's the output of smartctl -a on the relevant drive?

 

[Chris Moore]

scan: resilvered 1.02T in 0 days 04:36:50 with 0 errors on Tue Jul 10 01:29:33

You have not done a scrub since you resilvered and you had to replace a disk in July. Now, you have another disk problem.
How old are the drives? What size are they?

 

[surfrock66]

Drives are pretty old, probably 4 years. I did have a hard failure in July, but I have a scrub scheduled for the 1st of the month at 2AM, I don't see any indication it didn't run on 8/1?

Here's the smartctl -a output:

root@sr66-nas:~ # smartctl -a /dev/ada4
smartctl 6.6 2017-11-05 r4594 [FreeBSD 11.1-STABLE amd64] (local build)
Copyright (C) 2002-17, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF INFORMATION SECTION ===
Model Family: Western Digital Green
Device Model: WDC WD30EZRX-00DC0B0
Serial Number: WD-WMC1T2736354
LU WWN Device Id: 5 0014ee 00389eccf
Firmware Version: 80.00A80
User Capacity: 3,000,592,982,016 bytes [3.00 TB]
Sector Sizes: 512 bytes logical, 4096 bytes physical
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: 3.0 Gb/s)
Local Time is: Thu Aug 9 22:00:58 2018 PDT
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: ( 121) The previous self-test completed having
the read element of the test failed.
Total time to complete Offline
data collection: (40860) 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: ( 410) minutes.
Conveyance self-test routine
recommended polling time: ( 5) minutes.
SCT capabilities: (0x70b5) 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 200 200 051 Pre-fail Always - 0
3 Spin_Up_Time 0x0027 183 175 021 Pre-fail Always - 5816
4 Start_Stop_Count 0x0032 100 100 000 Old_age Always - 97
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 037 037 000 Old_age Always - 46417
10 Spin_Retry_Count 0x0032 100 253 000 Old_age Always - 0
11 Calibration_Retry_Count 0x0032 100 253 000 Old_age Always - 0
12 Power_Cycle_Count 0x0032 100 100 000 Old_age Always - 97
192 Power-Off_Retract_Count 0x0032 200 200 000 Old_age Always - 63
193 Load_Cycle_Count 0x0032 001 001 000 Old_age Always - 2389936
194 Temperature_Celsius 0x0022 129 104 000 Old_age Always - 21
196 Reallocated_Event_Count 0x0032 200 200 000 Old_age Always - 0
197 Current_Pending_Sector 0x0032 200 200 000 Old_age Always - 3
198 Offline_Uncorrectable 0x0030 200 200 000 Old_age Offline - 3
199 UDMA_CRC_Error_Count 0x0032 200 200 000 Old_age Always - 0
200 Multi_Zone_Error_Rate 0x0008 200 200 000 Old_age Offline - 4

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 90% 46397 411798217
# 2 Extended offline Completed: read failure 90% 46392 411798216
# 3 Short offline Completed without error 00% 46301 -
# 4 Short offline Completed without error 00% 46133 -
# 5 Extended offline Completed without error 00% 46045 -
# 6 Short offline Completed without error 00% 45941 -
# 7 Short offline Completed without error 00% 45845 -
# 8 Short offline Completed without error 00% 45749 -
# 9 Extended offline Completed without error 00% 12853 -
#10 Extended offline Interrupted (host reset) 10% 12752 -
#11 Extended offline Completed without error 00% 12602 -
#12 Extended offline Completed without error 00% 12411 -
#13 Extended offline Completed without error 00% 12243 -
#14 Extended offline Completed without error 00% 12091 -

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.


 

[Jailer]

That drive is failing smart tests. You should replace that drive ASAP.

 

[danb35]

I don't see any indication it didn't run on 8/1?

Here's the indication:

scan: resilvered 1.02T in 0 days 04:36:50 with 0 errors on Tue Jul 10 01:29:33 2018

The scrub didn't run for some reason, or it would have been listed here rather than the resilver when you replaced the disk. And, as @Jailer notes, the disk is failing SMART tests. The system should have warned you about that too, and that warrants immediate replacement. It's possible that the load cycle count of 2.4M has something to do with it.

 

[Chris Moore]

Do you have the system setup to make the disks go to sleep or spin down in order to try to save power because that load cycle count, 2.4 million is a bit unusual

Are all the drives WD Green? That would make a huge difference.

 

[Johnnie Black]

More likely never changed the default 8 sec head park timer on the green drives, this can result in a very high LCC.

 

[Chris Moore]

PS. You should post this kind of output using the CODE tag, not CMD tag so it looks better.

Code:

root@sr66-nas:~ # smartctl -a /dev/ada4
smartctl 6.6 2017-11-05 r4594 [FreeBSD 11.1-STABLE amd64] (local build)
Copyright (C) 2002-17, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF INFORMATION SECTION ===
Model Family:	 Western Digital Green
Device Model:	 WDC WD30EZRX-00DC0B0
Serial Number:	WD-WMC1T2736354
LU WWN Device Id: 5 0014ee 00389eccf
Firmware Version: 80.00A80
User Capacity:	3,000,592,982,016 bytes [3.00 TB]
Sector Sizes:	 512 bytes logical, 4096 bytes physical
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: 3.0 Gb/s)
Local Time is:	Thu Aug  9 22:00:58 2018 PDT
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:	  ( 121)	The previous self-test completed having
					the read element of the test failed.
Total time to complete Offline
data collection:		 (40860) 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:	 ( 410) minutes.
Conveyance self-test routine
recommended polling time:	 (   5) minutes.
SCT capabilities:			(0x70b5)	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   200   200   051	Pre-fail  Always	   -	   0
  3 Spin_Up_Time			0x0027   183   175   021	Pre-fail  Always	   -	   5816
  4 Start_Stop_Count		0x0032   100   100   000	Old_age   Always	   -	   97
  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   037   037   000	Old_age   Always	   -	   46417
 10 Spin_Retry_Count		0x0032   100   253   000	Old_age   Always	   -	   0
 11 Calibration_Retry_Count 0x0032   100   253   000	Old_age   Always	   -	   0
 12 Power_Cycle_Count	   0x0032   100   100   000	Old_age   Always	   -	   97
192 Power-Off_Retract_Count 0x0032   200   200   000	Old_age   Always	   -	   63
193 Load_Cycle_Count		0x0032   001   001   000	Old_age   Always	   -	   2389936
194 Temperature_Celsius	 0x0022   129   104   000	Old_age   Always	   -	   21
196 Reallocated_Event_Count 0x0032   200   200   000	Old_age   Always	   -	   0
197 Current_Pending_Sector  0x0032   200   200   000	Old_age   Always	   -	   3
198 Offline_Uncorrectable   0x0030   200   200   000	Old_age   Offline	  -	   3
199 UDMA_CRC_Error_Count	0x0032   200   200   000	Old_age   Always	   -	   0
200 Multi_Zone_Error_Rate   0x0008   200   200   000	Old_age   Offline	  -	   4

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	   90%	 46397		 411798217
# 2  Extended offline	Completed: read failure	   90%	 46392		 411798216
# 3  Short offline	   Completed without error	   00%	 46301		 -
# 4  Short offline	   Completed without error	   00%	 46133		 -
# 5  Extended offline	Completed without error	   00%	 46045		 -
# 6  Short offline	   Completed without error	   00%	 45941		 -
# 7  Short offline	   Completed without error	   00%	 45845		 -
# 8  Short offline	   Completed without error	   00%	 45749		 -
# 9  Extended offline	Completed without error	   00%	 12853		 -
#10  Extended offline	Interrupted (host reset)	  10%	 12752		 -
#11  Extended offline	Completed without error	   00%	 12602		 -
#12  Extended offline	Completed without error	   00%	 12411		 -
#13  Extended offline	Completed without error	   00%	 12243		 -
#14  Extended offline	Completed without error	   00%	 12091		 -

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.

 

[Chris Moore]

Drives are pretty old, probably 4 years.

You say all the drives are 4 years old and I am guessing they are all WD Green drives, but I think you should look more carefully at the SMART output from all the drives. They may be getting close to the EOL (end of life) or already passed it, and I think that it is time for you to start planning replacements. Here is why, based on the power on hours of the drive you shared with us, 46417, your drives are actually over 5 years of power on time.
I try to replace my drives at the 5 year mark because after 5 years they start to fail more frequently. That is a statistical fact based on the information from people that have many more drives than I ever will. However, I had a server full of drives that were in the same age range as yours last year and I ended up buying more than 30 drives (personally) between the last 6 months of 2017 and the first 3 months of 2018. I made the mistake of buying 8 Toshiba drives and 4 of them failed in the first 3 months I had them, and not wanting to deal with that going forward, I got rid of them and had to buy replacements for the replacements.

Long story short, I think that you are overdue for a new set of drives. You might be able to spread the purchase out over a few months, but you should be prepared to have one or two drives fail each month until you have replaced them all. That was what got me started, I was having a drive fail each month and then had two fail at the same time.