Preclear.sh results - Questions about your results? Post them here.


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Here's mine. Anything I should worry about?

 

============================================================================

S.M.A.R.T. error count differences detected after pre-clear

note, some 'raw' values may change, but not be an indication of a problem

54c54

<   1 Raw_Read_Error_Rate         0x002f   200   188051    Pre-fail   Always       -       16

---

>   1 Raw_Read_Error_Rate         0x002f   200   188051    Pre-fail   Always       -       27

============================================================================

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No problems.  It is very normal to have what are often called soft read errors and soft seek errors.  The drive system detects them, makes the appropriate adjustments, and retries them, usually successfully.  The important number here is 200, unchanged, essentially perfect for this drive.  At some point in the past, the read error rate did increase, perhaps because of thermal expansion or contraction, electrical disturbances, drive vibrations, who knows what, and the scaled rate dropped to 188 (as shown in the WORST value), which is still a long way from the failure point of 51.  It has since returned to normal, at 200.

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Thanks so much Rob for the analysis, and Joe for the utility! It's been a godsend, now that I'm using it with good drives.

 

I'm going to read through the thread now and see if I can figure out what everything means, so I don't have to bother anyone during future runs. I may even be able to help someone.

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Here are my results on my New Samsung 1TB drive:

 

===========================================================================

=                unRAID server Pre-Clear disk /dev/sdb

=                      cycle 1 of 1

= Disk Pre-Clear-Read completed                                DONE

= Step 1 of 10 - Copying zeros to first 2048k bytes            DONE

= Step 2 of 10 - Copying zeros to remainder of disk to clear it DONE

= Step 3 of 10 - Disk is now cleared from MBR onward.          DONE

= Step 4 of 10 - Clearing MBR bytes for partition 2,3 & 4      DONE

= Step 5 of 10 - Clearing MBR code area                        DONE

= Step 6 of 10 - Setting MBR signature bytes                    DONE

= Step 7 of 10 - Setting partition 1 to precleared state        DONE

= Step 8 of 10 - Notifying kernel we changed the partitioning  DONE

= Step 9 of 10 - Creating the /dev/disk/by* entries            DONE

= Step 10 of 10 - Testing if the clear has been successful.    DONE

= Disk Post-Clear-Read completed                                DONE

Disk Temperature: 38C, Elapsed Time:  18:10:51

============================================================================

==

== Disk /dev/sdb has been successfully precleared

==

============================================================================

S.M.A.R.T. error count differences detected after pre-clear

note, some 'raw' values may change, but not be an indication of a problem

72c72

< 200 Multi_Zone_Error_Rate  0x002a  252  252  000    Old_age  Always      -      0

---

> 200 Multi_Zone_Error_Rate  0x002a  100  100  000    Old_age  Always      -      0

============================================================================

 

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That's actually a little unusual, but not a problem!  The error rate is zero, and stayed zero.

 

What intrigues me is that the other manufacturers and even Samsung before this used 253 to indicate that the attribute had not been used yet, but apparently Samsung has found a need for another internal use, and reserved 253 for it, making 252 the new UNUSED marker.  The other thing that is a little odd is that they used a starting value of 100.  The general trend in modern drives is to use a scale of 1 to 200, whereas before they used 1 to 100.  You will often see in modern drives where some attributes, especially newer ones, use 200, whereas many of the oldest attributes still use 100.  Perhaps for Samsung, this IS an older, long used attribute.

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I figure I would join in the fun on my two drives that I cleared! Anything that I should be concerned about with these two drives?

 

============================================================================

==

== Disk /dev/sdj has been successfully precleared

==

============================================================================

S.M.A.R.T. error count differences detected after pre-clear

note, some 'raw' values may change, but not be an indication of a problem

68c68

< 190 Unknown_Attribute      0x0022  078  070  000    Old_age  Always

-      370540566

---

> 190 Unknown_Attribute      0x0022  076  070  000    Old_age  Always

-      420872216

75c75

< 201 Soft_Read_Error_Rate    0x000a  253  253  000    Old_age  Always

-      0

---

> 201 Soft_Read_Error_Rate    0x000a  100  100  000    Old_age  Always

-      0

============================================================================

 

 

============================================================================

==

== Disk /dev/sdc has been successfully precleared

==

============================================================================

S.M.A.R.T. error count differences detected after pre-clear

note, some 'raw' values may change, but not be an indication of a problem

54c54

<  1 Raw_Read_Error_Rate    0x000f  100  100  051    Pre-fail  Always

-      21

---

>  1 Raw_Read_Error_Rate    0x000f  100  099  051    Pre-fail  Always

-      10

63c63

<  13 Read_Soft_Error_Rate    0x000e  100  100  000    Old_age  Always

-      21

---

>  13 Read_Soft_Error_Rate    0x000e  100  099  000    Old_age  Always

-      10

68c68

< 190 Unknown_Attribute      0x0022  078  074  000    Old_age  Always

-      370540566

---

> 190 Unknown_Attribute      0x0022  075  074  000    Old_age  Always

-      437649433

75c75

< 201 Soft_Read_Error_Rate    0x000a  253  253  000    Old_age  Always

-      0

---

> 201 Soft_Read_Error_Rate    0x000a  100  100  000    Old_age  Always

-      0

============================================================================

 

 

 

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  • 3 weeks later...

See the attached screenshot. I cleared two disks simultaneously. The other disk just said it had been precleared successfully with no other data appearing. I assume that's a good thing.

No, that is not what it indicates at all.  The output is a "diff" between the starting SMART report and the ending SMART report.  If the original was failing, and the end is failing, then the drive did not change, but according to SMART it could be failing.
This disk, on the other hand showed a few things. Any help/disaster warnings appreciated.

You are correct, a few values changed from the pre SMART report to the POST report...

 

I suggest you read back in this thread on how to interpret the results.  It has been described several times.

However... be forewarned... I can almost guarantee the second drive will fail sometime in the next 750,000 hours of operation.  ;)

 

Joe L.

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  • 2 months later...

Okay, this is the first preclear of a Hitachi Deskstar 2TB 7200rpm drive, model HD32000IDK7.  Am I correct in assuming this drive is healthy?  Why did the value go from 95 up to 100 after the preclear?

 

===========================================================================
=                unRAID server Pre-Clear disk /dev/sda
=                       cycle 1 of 1
= Disk Pre-Clear-Read completed                                 DONE
= Step 1 of 10 - Copying zeros to first 2048k bytes             DONE
= Step 2 of 10 - Copying zeros to remainder of disk to clear it DONE
= Step 3 of 10 - Disk is now cleared from MBR onward.           DONE
= Step 4 of 10 - Clearing MBR bytes for partition 2,3 & 4       DONE
= Step 5 of 10 - Clearing MBR code area                         DONE
= Step 6 of 10 - Setting MBR signature bytes                    DONE
= Step 7 of 10 - Setting partition 1 to precleared state        DONE
= Step 8 of 10 - Notifying kernel we changed the partitioning   DONE
= Step 9 of 10 - Creating the /dev/disk/by* entries             DONE
= Step 10 of 10 - Testing if the clear has been successful.     DONE
= Disk Post-Clear-Read completed                                DONE
Disk Temperature: 42C, Elapsed Time:  27:22:47
============================================================================
==
== Disk /dev/sda has been successfully precleared
==
============================================================================
S.M.A.R.T. error count differences detected after pre-clear
note, some 'raw' values may change, but not be an indication of a problem
19,20c19,20
< Offline data collection status:  (0x80)       Offline data collection activity
<                                       was never started.
---
> Offline data collection status:  (0x84)       Offline data collection activity
>                                       was suspended by an interrupting command
from host.
52c52
<   1 Raw_Read_Error_Rate     0x000b   095   095   016    Pre-fail  Always
-       1114112
---
>   1 Raw_Read_Error_Rate     0x000b   100   100   016    Pre-fail  Always
-       0
============================================================================

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hi, i ran preclear on a 1.5TB ... it took 27:22:16 to complet 

 

there were some error/warnings(??) at the end

 

===========================================================================
=                unRAID server Pre-Clear disk /dev/sda
=                       cycle 1 of 1
= Disk Pre-Clear-Read completed                                 DONE
= Step 1 of 10 - Copying zeros to first 2048k bytes             DONE
= Step 2 of 10 - Copying zeros to remainder of disk to clear it DONE
= Step 3 of 10 - Disk is now cleared from MBR onward.           DONE
= Step 4 of 10 - Clearing MBR bytes for partition 2,3 & 4       DONE
= Step 5 of 10 - Clearing MBR code area                         DONE
= Step 6 of 10 - Setting MBR signature bytes                    DONE
= Step 7 of 10 - Setting partition 1 to precleared state        DONE
= Step 8 of 10 - Notifying kernel we changed the partitioning   DONE
= Step 9 of 10 - Creating the /dev/disk/by* entries             DONE
= Step 10 of 10 - Testing if the clear has been successful.     DONE
= Disk Post-Clear-Read completed                                DONE
Disk Temperature: 41C, Elapsed Time:  27:22:16
============================================================================
==
== Disk /dev/sda has been successfully precleared
==
============================================================================
S.M.A.R.T. error count differences detected after pre-clear
note, some 'raw' values may change, but not be an indication of a problem
54c54
<   1 Raw_Read_Error_Rate     0x002f   100   253   051    Pre-fail  Always                                                                                                                                      -       0
---
>   1 Raw_Read_Error_Rate     0x002f   200   200   051    Pre-fail  Always                                                                                                                                      -       0
63c63
< 193 Load_Cycle_Count        0x0032   200   200   000    Old_age   Always                                                                                                                                      -       36
---
> 193 Load_Cycle_Count        0x0032   200   200   000    Old_age   Always                                                                                                                                      -       37
67c67
< 199 UDMA_CRC_Error_Count    0x0032   200   253   000    Old_age   Always                                                                                                                                      -       0
---
> 199 UDMA_CRC_Error_Count    0x0032   200   200   000    Old_age   Always                                                                                                                                      -       0
============================================================================

 

pls help me interpret these messages ...

 

btw, i'm running preclear on a 2TB, it's 95% complete, elapsed 34:01:10

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If you look here the value 253 refers to the drive being completely virgin and brand new.  After your first cycle, that value drops to 200 indicating that the drive has no failures, but is no longer new.  That SMART report looks clean to me, and I would bet that your second or third cycle will contain no changes.

 

What 2TB drive are you using?  I have 2 of them running 10 cycles atm and they are averaging about 28 hours for a full cycle.  The old mobo I'm using is only SATA 150.

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What 2TB drive are you using?  I have 2 of them running 10 cycles atm and they are averaging about 28 hours for a full cycle.  The old mobo I'm using is only SATA 150.

You are the first person I've read about who has run as long a test.  280 hours is a pretty decent burn in period..(nearly 12 days). 

 

Odds are you'll uncover any marginal hardware issues.  Good luck.  Sounds like you have a good handle on how to interpret the results.

 

Joe L.

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  • 2 weeks later...

Okay, this is the first preclear of a Hitachi Deskstar 2TB 7200rpm drive, model HD32000IDK7.  Am I correct in assuming this drive is healthy?  Why did the value go from 95 up to 100 after the preclear?

 

<   1 Raw_Read_Error_Rate     0x000b   095   095   016    Pre-fail  Always -       1114112
---
>   1 Raw_Read_Error_Rate     0x000b   100   100   016    Pre-fail  Always -       0

 

That is really odd!  Thanks for picking up on that, I have never seen that happen before.  In particular, the WORST value is NEVER supposed to increase.  The read error rate appears to have been reset completely, which I think may be a minor bug in the firmware for this drive model and firmware version.  I suppose the manufacturers have a way to reset some values on refurbished drives, but that still seems like tampering with the speedometer before a resale.

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<   1 Raw_Read_Error_Rate     0x002f   100   253   051    Pre-fail  Always      -       0
>   1 Raw_Read_Error_Rate     0x002f   200   200   051    Pre-fail  Always      -       0

< 199 UDMA_CRC_Error_Count    0x0032   200   253   000    Old_age   Always  -       0
> 199 UDMA_CRC_Error_Count    0x0032   200   200   000    Old_age   Always  -       0

 

I would like to suggest to Joe that he add a little normalization to these line comparisons.  If the value(s) in the VALUE or WORST columns are 200 or 253, then replace them with 100, and then compare them (but keep the original for display).  This will eliminate some confusion, since these are not actually SMART value changes, just initializations.  The only extremely remote case where this may not work as expected is with a few older Maxtor drives, that actually use a scale from 253 down to 1, but I don't think this would matter.  All others are scaled from either 200 or 100.

 

I would also suggest dropping the 240's and perhaps others, or at least find a way to 'deprecate' them, so if they exist and are different, are not given any significance.

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<   1 Raw_Read_Error_Rate     0x002f   100   253   051    Pre-fail  Always      -       0
>   1 Raw_Read_Error_Rate     0x002f   200   200   051    Pre-fail  Always      -       0

< 199 UDMA_CRC_Error_Count    0x0032   200   253   000    Old_age   Always  -       0
> 199 UDMA_CRC_Error_Count    0x0032   200   200   000    Old_age   Always  -       0

 

I would like to suggest to Joe that he add a little normalization to these line comparisons.  If the value(s) in the VALUE or WORST columns are 200 or 253, then replace them with 100, and then compare them (but keep the original for display).  This will eliminate some confusion, since these are not actually SMART value changes, just initializations.  The only extremely remote case where this may not work as expected is with a few older Maxtor drives, that actually use a scale from 253 down to 1, but I don't think this would matter.  All others are scaled from either 200 or 100.

 

I would also suggest dropping the 240's and perhaps others, or at least find a way to 'deprecate' them, so if they exist and are different, are not given any significance.

I've been thinking on how to improve the report... it clearly is confusing too many.   I'm thinking of only extracting the reallocated sectors and changes in the error logging area unless a measurement is actually FAILING.

 

Problem is, experienced users will want to see more.

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I've been thinking on how to improve the report... it clearly is confusing too many.   I'm thinking of only extracting the reallocated sectors and changes in the error logging area unless a measurement is actually FAILING.

 

Problem is, experienced users will want to see more.

 

I know there is a -v option already that prints the version but perhaps that could become -v for "verbose mode output"?  Make the default to not be verbose and then allow the more experienced users to have the option to see everything by specifying -v.

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My company just purchased one of Lime's MD1500 servers and I am trying to preclear all our new drives..... Could you please advise on if I should be concerned with the the below results.. I already have 1(of 5) drives that are confirmed dead via SMART reporting

 

S.M.A.R.T. error count differences detected after pre-clear

note, some 'raw' values may change, but not be an indication of a problem

58c58

< 7 Seek_Error_Rate 0x002e 100 253 000 Old_age Always

- 0

---

> 7 Seek_Error_Rate 0x002e 200 200 000 Old_age Always

- 0

63c63

< 193 Load_Cycle_Count 0x0032 200 200 000 Old_age Always

- 100

---

> 193 Load_Cycle_Count 0x0032 200 200 000 Old_age Always

- 101

65c65

< 197 Current_Pending_Sector 0x0032 200 200 000 Old_age Always

- 1

---

> 197 Current_Pending_Sector 0x0032 200 200 000 Old_age Always

- 0

============================================================================

root@unraid:/boot#

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The 253 on the first drive is an initialization value indicating the drive has never been used before.  The other drives look fine.  It's odd that you had a dead drive from Limetech, as they supposedly preclear the drives themselves before shipment.  Did you buy the drives from somewhere else?

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The 253 on the first drive is an initialization value indicating the drive has never been used before.  The other drives look fine.  It's odd that you had a dead drive from Limetech, as they supposedly preclear the drives themselves before shipment.  Did you buy the drives from somewhere else?

 

Yes we purchased a Naked array from Lime and purchased all our drive from NewEgg....... Thanks for the response on the drive... I thought it looked OK, but another drive showed a lot less changes than this drive did so it just had me a little concerned. I really hate dealing with hard drives as I work for a small company (less than 100 employees) yet it seems like I'm always dealing with dead drives and often times its on brand new ones as well.  Sometimes I think these company just gave up on making reliable drives and only care about the size these days. I'm dealing with a possible failing drive on my home unraid server as well..

 

 

 

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A few preclear cycles should clear up any worries about a new drive.  Either it's stable, or it's not.  As far as the fail rate goes, I think the manufacturers are playing the consumer market like a song.  We constantly replace drives because new capacities are released, or because a drive fails in 3 years.  Planned obsolescence?

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  • 2 weeks later...

Hey folks,

 

Just precleared an older Seagate 1TB drive. Tried to interpret these numbers, but I'm having trouble making heads or tails of them...

 

<   1 Raw_Read_Error_Rate     0x000f   117   099   006    Pre-fail  Always     -       147540226
---
>   1 Raw_Read_Error_Rate     0x000f   108   099   006    Pre-fail  Always     -       16402173
59c59
<   7 Seek_Error_Rate         0x000f   060   056   030    Pre-fail  Always     -       231985297980
---
>   7 Seek_Error_Rate         0x000f   060   056   030    Pre-fail  Always     -       236280364147
65,67c65,67
< 189 High_Fly_Writes         0x003a   099   099   000    Old_age   Always     -       1
< 190 Airflow_Temperature_Cel 0x0022   075   053   045    Old_age   Always     -       25 (Lifetime Min/Max 23/25)
< 195 Hardware_ECC_Recovered  0x001a   039   019   000    Old_age   Always     ---
> 189 High_Fly_Writes         0x003a   098   098   000    Old_age   Always     -       2
> 190 Airflow_Temperature_Cel 0x0022   075   053   045    Old_age   Always     -       25 (Lifetime Min/Max 23/26)
> 195 Hardware_ECC_Recovered  0x001a   050   019   000    Old_age   Always 

 

Thanks for any advice!

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