Offline uncorrectable sectors and Currently unreadable (pending) sectors

[thinking21]

Hi,

Sorry if this is a noob question,

I currently have 4 WD Green hard drives 1.5 TB in a zpool with raidz1-0 running freenas 9.1

[root@freenas] ~# zpool status
pool: share
state: ONLINE
scan: none requested
config:

NAME STATE READ WRITE CKSUM
share ONLINE 0 0 0
raidz1-0 ONLINE 0 0 0
gptid/48371114-4f67-11e2-a4b3-f46d0462721f ONLINE 0 0 0
gptid/49184180-4f67-11e2-a4b3-f46d0462721f ONLINE 0 0 0
gptid/4a0588c8-4f67-11e2-a4b3-f46d0462721f ONLINE 0 0 0
gptid/4ad03973-4f67-11e2-a4b3-f46d0462721f ONLINE 0 0 0

errors: No known data errors
I'eve been getting these following errors for days now on the console:
Aug 23 17:39:49 freenas smartd[2155]: Device: /dev/ada0, 4 Currently unreadable (pending) sectors
Aug 23 17:39:49 freenas smartd[2155]: Device: /dev/ada0, 25 Offline uncorrectable sectors
From looking around online, I think this could mean that drive is failing. Can someone confirm from the smart output? Thanks in advance.
[root@freenas] ~# smartctl -A /dev/ada0
smartctl 6.1 2013-03-16 r3800 [FreeBSD 9.1-STABLE amd64] (local build)
Copyright (C) 2002-13, 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 200 200 051 Pre-fail Always - 0
3 Spin_Up_Time 0x0027 177 176 021 Pre-fail Always - 4141
4 Start_Stop_Count 0x0032 100 100 000 Old_age Always - 30
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 093 093 000 Old_age Always - 5227
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 - 29
192 Power-Off_Retract_Count 0x0032 200 200 000 Old_age Always - 10
193 Load_Cycle_Count 0x0032 187 187 000 Old_age Always - 40118
194 Temperature_Celsius 0x0022 118 116 000 Old_age Always - 29
196 Reallocated_Event_Count 0x0032 200 200 000 Old_age Always - 0
197 Current_Pending_Sector 0x0032 200 200 000 Old_age Always - 4
198 Offline_Uncorrectable 0x0030 200 200 000 Old_age Offline - 25
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 - 31

 

[cyberjock]

Yep. Your disk is bad. You should do the following.

1. Punch yourself in the face. You went with RAIDZ1 and that is data-seppuku(and pretty much as been since 2009). Read the article in my signature and you'll see why you are probably about to lose some data. How much is anybody's guess.
2. Admit you've screwed up and start backing up the most important data on your zpool. Right now.
3. Check your hard drive serial number with the manufacturer to see if it is in warranty. If it is, great.
4. Run a long SMART test (smartctl -a /dev/ada0). It'll fail that for sure.
5. Now your drive qualifies for the RMA. Do the RMA.
6. Get a new disk(don't wait the 2 weeks for the new disk to arrive). You already have no protection from even a URE. If you don't know what a URE is then you didn't read the article I said to read in #1. In that case, go back and read the article. For real this time. Now order a new disk. If you can buy one locally I'd absolutely do that. You do NOT want to delay this.
7. Do the disk replacement in accordance with the FreeNAS manual. At this point you should pray to the data-gods that they may grace your hard drive with long life and no errors during the resilvering process.
8. When the new disk from the RMA arrives in the mail set it aside as an emergency spare.
9. Promise yourself you will never go with RAIDZ1 again. It's only a bad idea that is more stupid as each day passes.
10. Use the wdidle tool on your drive to change the Intellpark setting to 300 seconds. Your Load cycle count gave away the fact that you haven't made this critical change to make these "desktop" drives more compatible with "servers". If you don't do this, WD will basically know that you aren't using them in a desktop and can deny your warranty because you are using the disks outside of their designed function. This will also extend the life of your drives.

 

[thinking21]

Thanks for the very detailed feedback. I've read the article you pointed out.
Will proceed with changing the Intelpark setting to 300s on all the drives as you pointed out. Moving forward, I am probably going to try to move whatever I can off to an external hard drive temporarily and rebuild the zpool with RAIDZ2 or higher. This is probably best in the long run.

Yep. Your disk is bad. You should do the following.

1. Punch yourself in the face. You went with RAIDZ1 and that is data-seppuku(and pretty much as been since 2009). Read the article in my signature and you'll see why you are probably about to lose some data. How much is anybody's guess.
2. Admit you've screwed up and start backing up the most important data on your zpool. Right now.
3. Check your hard drive serial number with the manufacturer to see if it is in warranty. If it is, great.
4. Run a long SMART test (smartctl -a /dev/ada0). It'll fail that for sure.
5. Now your drive qualifies for the RMA. Do the RMA.
6. Get a new disk(don't wait the 2 weeks for the new disk to arrive). You already have no protection from even a URE. If you don't know what a URE is then you didn't read the article I said to read in #1. In that case, go back and read the article. For real this time. Now order a new disk. If you can buy one locally I'd absolutely do that. You do NOT want to delay this.
7. Do the disk replacement in accordance with the FreeNAS manual. At this point you should pray to the data-gods that they may grace your hard drive with long life and no errors during the resilvering process.
8. When the new disk from the RMA arrives in the mail set it aside as an emergency spare.
9. Promise yourself you will never go with RAIDZ1 again. It's only a bad idea that is more stupid as each day passes.
10. Use the wdidle tool on your drive to change the Intellpark setting to 300 seconds. Your Load cycle count gave away the fact that you haven't made this critical change to make these "desktop" drives more compatible with "servers". If you don't do this, WD will basically know that you aren't using them in a desktop and can deny your warranty because you are using the disks outside of their designed function. This will also extend the life of your drives.