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


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According to SMART, if the normalized value (in this case 60) is above the failure threshold (30) the disk is healthy.

 

I'd keep an eye on the drive and see if the normalized value increases, or decreases over time.  It might be that it will improve over time as it breaks in...      If the normalized value continues to drop towards 30 in the next few months, then you might want to replace it.

 

The two disks may be running different firmware.  the first started at 253.  The second (apparently) at 100. (unless that is the pre-process current normalized value vs. the post-process normalized value, in which case I'm wrong and in need of a second cup of coffee)

 

Joe L.

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Dear Joe,

 

thanks for your quick reply

 

According to SMART, if the normalized value (in this case 60) is above the failure threshold (30) the disk is healthy.

That is nice to hear

 

 

I'd keep an eye on the drive and see if the normalized value increases, or decreases over time.  It might be that it will improve over time as it breaks in...      If the normalized value continues to drop towards 30 in the next few months, then you might want to replace it.

I will do this.

 

 

The two disks may be running different firmware.  the first started at 253.  The second (apparently) at 100. (unless that is the pre-process current normalized value vs. the post-process normalized value, in which case I'm wrong and in need of a second cup of coffee)

 

Joe L.

Sorry I do not understand the meaning of this. Both disks started with the same values:

 

ID# ATTRIBUTE_NAME          FLAG     VALUE WORST THRESH TYPE      UPDATED  WHEN_FAILED RAW_VALUE
  7 Seek_Error_Rate         0x000f   100   253   030    Pre-fail  Always       -       5662

 

The first disks "Seek_error_Rate" didn't change after 3 cycles preclear. The second disk's value changed as mentioned above.

 

Kind regards

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I just finished my first preclear runs on my first 2 disks.

 

I did 3 cycles on both of my Seagate 3TB Barracuda ST3000DM001 disks.

It looks like it passed the tests, but I would feel better if any of you Pros could take a look please.

 

For the future, at which values should I look, to see if a drive is safe to use?

 

I added the Preclear_Start Results on Pastebin, since I am only allowed to add 4 attachments.

 

Preclear_Start_W1F1TER1

Preclear_Start_W1F1Z6L1

preclear_finish__W1F1TER1_2013-05-12.txt

preclear_finish__W1F1Z6L1_2013-05-12.txt

preclear_rpt__W1F1TER1_2013-05-12.txt

preclear_rpt__W1F1Z6L1_2013-05-12.txt

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I just finished my first preclear runs on my first 2 disks.

 

For the future, at which values should I look, to see if a drive is safe to use?

For the most part you are looking for ANY individual parameter that is FAILING_NOW  (that would be bad)

And, you are looking for re-allocated sectors, or sectors pending re-allocation.    The "raw" counts on those columns are actual counts.

 

The "raw" column on many parameters is meaningful to only the manufacturer.  Do not worry if you see raw read errors, ALL drives have them, some report them, some do not.

 

If you see the "normalized" value changing in value and getting closer to the affiliated error threshold, be attentive to the rate of change.  Exception are those parameters where the failure threshold is only a few counts from the initial starting value.  (spin-up-retry failure is often set very close to the initial value, as only a few failures to spin up to speed indicates a drive that is pending a possible complete failure)

 

Many manufacturers have factory starting values of 253, and change to 100 or 200 once the drive has a few hours on it.  This is perfectly normal.

 

Any sectors pending re-allocation AFTER a preclear  are particularly bad.  Any un-readable sectors identified in the pre-read phase should have been re-allocated in the zeroing (writing) phase.  Any remaining after the preclear would have been identified in the post-read phase. (indicating what was written could not be read back)  An additional pre-clear should be performed, and if the numbers do not stabilize (additional non-readable sectors are found) then the disk should be returned as defective.

 

Your disks looked perfectly normal to me.

 

Joe L.

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Thank you very much for this detailed and lenghty information.

 

Maybe you want to add some of this info to the preclear-script thread, so that newbies as myself, know what to look for, after their preclear cycles are finished.

 

Really appreciate the knowledgesharing!

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Thank you very much for this detailed and lenghty information.

 

Maybe you want to add some of this info to the preclear-script thread, so that newbies as myself, know what to look for, after their preclear cycles are finished.

 

Really appreciate the knowledgesharing!

As suggested, I added what to look for into the thread where you downloaded the preclear script.
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I just finished my first preclear runs on my first 2 disks.

...

Your disks looked perfectly normal to me.

Except, maybe, the Read performance--it's too fast :).

ST3000DM001

== Last Cycle's Pre Read Time  : 3:58:51 (209 MB/s)

== Last Cycle's Zeroing time  : 5:16:21 (158 MB/s)

== Last Cycle's Post Read Time : 13:56:02 (59 MB/s)

== Last Cycle's Total Time    : 19:13:23

Specifically, the Pre Read Time speed. 209 MB/s as an AVERAGE for the entire drive, is fantastic.

 

I'd have expected something closer to 150-160.

 

"There's something going on here, but I don't know what it is ..."

 

Ideas?

 

 

 

 

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I just finished my first preclear runs on my first 2 disks.

...

Your disks looked perfectly normal to me.

Except, maybe, the Read performance--it's too fast :).

ST3000DM001

== Last Cycle's Pre Read Time  : 3:58:51 (209 MB/s)

== Last Cycle's Zeroing time  : 5:16:21 (158 MB/s)

== Last Cycle's Post Read Time : 13:56:02 (59 MB/s)

== Last Cycle's Total Time    : 19:13:23

Specifically, the Pre Read Time speed. 209 MB/s as an AVERAGE for the entire drive, is fantastic.

 

I'd have expected something closer to 150-160.

 

"There's something going on here, but I don't know what it is ..."

 

Ideas?

Since he had run multiple cycles, the odds are some of what was "read" was from the linux buffer cache and not from the physical disk.  (it would skew the speed calcs a bit towards the high side)  Even so, that could only be a few GB, so it is impressive.
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Since he had run multiple cycles, the odds are some of what was "read" was from the linux buffer cache and not from the physical disk.

Those odds are 0.00 (at least, with Powerball, you have > 0 odds :))

The buffer cache keeps the most recent data. Doesn't preclear.sh do strictly increasing-LBA sequential operations (for all buffered I/O) ?

 

[Regardless, as you noted, (even in the most optimally perverse case,) a few "fast" GB out of 3TB would have immeasurable negligible effect.]

 

 

 

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Specifically, the Pre Read Time speed. 209 MB/s as an AVERAGE for the entire drive, is fantastic.

I was amazed myself aswell.

There are many reasons for a disk to perform below its specs. But there are hardly any reasons for a disk to perform above its specs, especially by the amount indicated in your report. Not only that, but it is not just the one disk, but both! (The other disk is only 20-25% over spec [vs ~30% for the quoted one].)

 

Additionally, both 3rd passes are notably faster than the average for all 3 passes.

 

Far-fetched as it seems, I've got to ask ... Did you set the system clock (back by about 1 hour) sometime Saturday morning? :) [via date -s XXX]

 

 

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Haha, maybe your Idea isn´t that far fetched after all.

It could very well be....Since I was still playing around with the settings (but always through the WebUI, not via Console) while I was doing the Preclears. Preclearing the drives was pretty much the first thing I did when I booted up my server for the first time ever.

 

Although I think I already had the time-settings already set up, it might be the only logical explanation.

Because whenever I checked on the Preclears I saw speeds of about 150-170 MB/s, which would make it very hard to get an average of 200 MB/s.

 

You Sir, think like a Detective  ;D

 

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Haha, maybe your Idea isn´t that far fetched after all.

It could very well be....

You Sir, think like a Detective  ;D

Thanks. But I must ... Murphy is a master criminal--and, even when you're good/lucky enough to catch him, he never goes to jail. :)

 

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Just completed 3 clears and things look good, just one question regarding the output near_thresh.

 

based on what is written in the actual preclear thread, this is just because the new value changed and is within 25 of the failure threshhold, for instance,

 

Spin_Retry_Count =  100    100          97        near_thresh 0

        End-to-End_Error =  100    100          99        near_thresh 0

          High_Fly_Writes =    96    100            0        ok          4

  Airflow_Temperature_Cel =    62      71          45        near_thresh 38

      Temperature_Celsius =    38      29            0        ok          38

 

 

all 3 had something similar to this.  otherwise, no smart failing and zeros for all the below values.  To the best of my knowledge, this is all good right?

 

thanks

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Just completed 3 clears and things look good, just one question regarding the output near_thresh.

 

based on what is written in the actual preclear thread, this is just because the new value changed and is within 25 of the failure threshhold, for instance,

 

Spin_Retry_Count =  100    100          97        near_thresh 0

        End-to-End_Error =  100    100          99        near_thresh 0

          High_Fly_Writes =    96    100            0        ok          4

  Airflow_Temperature_Cel =    62      71          45        near_thresh 38

      Temperature_Celsius =    38      29            0        ok          38

 

Correct. Nothing is wrong when the manufacturer puts the failure threshold very near to the starting value of the normalized value. 

all 3 had something similar to this.  otherwise, no smart failing and zeros for all the below values.  To the best of my knowledge, this is all good right?

Right.  It is not a problem.

thanks

You are welcome.
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  • 2 weeks later...

ARGGH!!

 

I stupidly initiated a Guest shutdown of my Unraid VM while the pre-clear was running. The good news is, it looks like the shutdown didn't proceed... If for some reason the shutdown does happen, is my pre-clear in risk of any danger? i'm 53% into stage 10 of 10; on cycle 2 of 3...

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ARGGH!!

 

I stupidly initiated a Guest shutdown of my Unraid VM while the pre-clear was running. The good news is, it looks like the shutdown didn't proceed... If for some reason the shutdown does happen, is my pre-clear in risk of any danger? i'm 53% into stage 10 of 10; on cycle 2 of 3...

you should be fine (unless it does eventually proceed)
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ARGGH!!

 

I stupidly initiated a Guest shutdown of my Unraid VM while the pre-clear was running. The good news is, it looks like the shutdown didn't proceed... If for some reason the shutdown does happen, is my pre-clear in risk of any danger? i'm 53% into stage 10 of 10; on cycle 2 of 3...

you should be fine (unless it does eventually proceed)

 

so far, looks OK - still running on cycle 3; now 10 of 10, at about 20%... my webui is gone, i'm hoping that when this finishes, i can still safely shutdown.

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OK so the pre-clear finished; I used the powerdown@ script at root ... either that or the VMTools somehow managed to stop the array and shut down cleanly.

 

Some of the results seem high, this is a refurb drive, do they keep the smart values from whatever previous failure?

 


      Raw_Read_Error_Rate =   112     100            6        ok          49924603
         Spin_Retry_Count =   100     100           97        near_thresh 0
         End-to-End_Error =   100     100           99        near_thresh 0
  Airflow_Temperature_Cel =    65      67           45        near_thresh 35
      Temperature_Celsius =    35      33            0        ok          35
   Hardware_ECC_Recovered =    51     100            0        ok          49924603
No SMART attributes are FAILING_NOW

0 sectors were pending re-allocation before the start of the preclear.
0 sectors were pending re-allocation after pre-read in cycle 1 of 3.
0 sectors were pending re-allocation after zero of disk in cycle 1 of 3.
0 sectors were pending re-allocation after post-read in cycle 1 of 3.
0 sectors were pending re-allocation after zero of disk in cycle 2 of 3.
0 sectors were pending re-allocation after post-read in cycle 2 of 3.
0 sectors were pending re-allocation after zero of disk in cycle 3 of 3.
0 sectors are pending re-allocation at the end of the preclear,
    the number of sectors pending re-allocation did not change.
0 sectors had been re-allocated before the start of the preclear.
0 sectors are re-allocated at the end of the preclear,
    the number of sectors re-allocated did not change.

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OK so the pre-clear finished; I used the powerdown@ script at root ... either that or the VMTools somehow managed to stop the array and shut down cleanly.

 

Some of the results seem high, this is a refurb drive, do they keep the smart values from whatever previous failure?

 


      Raw_Read_Error_Rate =   112     100            6        ok          49924603
         Spin_Retry_Count =   100     100           97        near_thresh 0
         End-to-End_Error =   100     100           99        near_thresh 0
  Airflow_Temperature_Cel =    65      67           45        near_thresh 35
      Temperature_Celsius =    35      33            0        ok          35
   Hardware_ECC_Recovered =    51     100            0        ok          49924603
No SMART attributes are FAILING_NOW

0 sectors were pending re-allocation before the start of the preclear.
0 sectors were pending re-allocation after pre-read in cycle 1 of 3.
0 sectors were pending re-allocation after zero of disk in cycle 1 of 3.
0 sectors were pending re-allocation after post-read in cycle 1 of 3.
0 sectors were pending re-allocation after zero of disk in cycle 2 of 3.
0 sectors were pending re-allocation after post-read in cycle 2 of 3.
0 sectors were pending re-allocation after zero of disk in cycle 3 of 3.
0 sectors are pending re-allocation at the end of the preclear,
    the number of sectors pending re-allocation did not change.
0 sectors had been re-allocated before the start of the preclear.
0 sectors are re-allocated at the end of the preclear,
    the number of sectors re-allocated did not change.

Looks like a perfectly healthy drive.
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Hi, I was looking through the last couple of pages and it seems like this new drive I just did a 1 round preclear on, is pretty similar to axeman's, but the seek error rate and raw read error rate seem really, really high.  I know the important reallocated markers are 0.  Should I just consider this a healthy drive and use it as normal?  It is a Seagate removed from an enclosure.  I also did a preclear on a 2TB refurb WD drive that has way better looking numbers.

 

 

Thanks for your input!

preclear_results-3tb6-4-13.txt

Fatboy_2TB_WD-WMC300165370_preclear_results.txt

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