I've gathered from reading some posts on here, that to potentially fix some disk errors, indicated by this smart test, I should pre-clear the disk and rebuild it.

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   191   191   051    Pre-fail  Always       -       30472
  3 Spin_Up_Time            0x0027   172   165   021    Pre-fail  Always       -       6391
  4 Start_Stop_Count        0x0032   099   099   000    Old_age   Always       -       1291
  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   071   071   000    Old_age   Always       -       21333
10 Spin_Retry_Count        0x0032   100   100   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       -       94
192 Power-Off_Retract_Count 0x0032   200   200   000    Old_age   Always       -       54
193 Load_Cycle_Count        0x0032   020   020   000    Old_age   Always       -       540848
194 Temperature_Celsius     0x0022   123   095   000    Old_age   Always       -       27
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      -       1
199 UDMA_CRC_Error_Count    0x0032   200   200   000    Old_age   Always       -       0
200 Multi_Zone_Error_Rate   0x0008   190   186   000    Old_age   Offline      -       2693

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%     21332         3655872265
# 2  Short offline       Completed: read failure       90%     21332         3655872266

 

I found this on another thread:

If you do not trust the drive, or want to put it through a good test:

un-assign it from the array

run the preclear_disk.sh script on it, then run the preclear_script.sh on it a second time.

then re-assign it to the array and let parity be re-constructed to it.

(as long as the results do not show additional sectors that are un-readable)

 

You array will be without parity protection while you clear and test the drive, but it sounds as if it will give you a lot of piece of mind.

 

After I un-assign it, can I restart the array with the disk missing? I understand the risk of running with the drive missing, I just want to know if it's possible, and how to do so?  Do I just restart the array with the disk not assigned, and it'll know what to do?  I'm still running 4.7...

 

Thanks in advance for your tips..

you might want to read this post:

 

http://lime-technology.com/forum/index.php?topic=27969.msg248016#msg248016

 

that I wrote about my experience with a high MZER situation.  Based on it I am guessing your drive won't be long for this world.

 

Regards,

 

Stephen

Interesting, mine is also a 2T WD Green.  Probably means nothing, but interesting..

 

So - I need to replace it.  Turns out my cache drive also has a high number of errors - I ran tests on all of them after posting this.  So I've got two drives on the way...  Thanks.