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


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I just finished preclearing my 3 TB drive but I am a little concerned because I have been told that 'reallocation' is a bad thing. I attached my syslog, but here is the part that made me thinking:

 

Jan 13 00:15:55 Tower preclear_disk-diff[11408]:  0 sectors were pending re-allocation before the start of the preclear.
Jan 13 00:15:55 Tower preclear_disk-diff[11408]:  16 sectors were pending re-allocation after pre-read in cycle 1 of 1.
Jan 13 00:15:55 Tower preclear_disk-diff[11408]:  0 sectors were pending re-allocation after zero of disk in cycle 1 of 1.

 

This is a new disk, and it appears there was a small region with sectors not correctly initialized.  Perhaps there had been an electrical spike that scrambled them?  I don't know.  But the zeroing phase appears to have had no problems rewriting them, so they are correct now.

 

Why not preclear the disk one more time, to reassure yourself that the disk is fine.  I really doubt you will see any further issues with this disk.

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I can't remember if I discovered that I had a bad memory stick before or after I ran the preclear.  Could this would have caused bad results (if the bad stick was still in the machine)?  Regardless, I am waiting for the new memory sticks to arrive, and then I am going to run the test again.  Should I run the test with all the drives connected to the same slots, and review the results (maybe there is a chance the results would be different.... I am not sure how memory is allocated during the testing prior.... maybe sdd got allocated bad sections of memory? I am Totally guessing on this).  Then if I get similar results to those posted, I could switch the drives around (different slots), and see what type of results I get.

I don't see any connection with memory here.  I'll just add though that if I have any suspicions at all about the memory of a computer, then I consider that computer to be completely unusable!  Period.  When you get the new memory sticks, test them with memtest overnight, until you are completely confident in them.

 

By the way all the drives are connected to on board SATA slots.  My first thought is that they should all have similar band widths, but maybe certain slots are designed, or are designated for higher bandwidth.

That pretty well rules out bandwidth differences, unless there was an issue with that specific port or cable.  You might try preclearing the slow drive one more time connected to the cable and port used by one of the faster drives.  And if you have the syslog during the slow drives preclear, check it for any drive-related errors/exceptions.

 

Rob,

 

I got the new memory in and then ran memtest for over night.  I then ran a preclear on the same drives in the same slot.  I got the same results as the reports I previously provided.  I then switched moved the drive in sdd (the slowest drive) to sda and moved the drive in sda (the fastest drive) to sdd.  I then ran the preclear again and I got similar results (the slowest drive was still finished 2 hours later) So it seems it is not a cable or slot issue.

 

I attached all three runs of the slow drive (Z2F0KS4Z) and one report of the fast drive (Z1E2EQXS) when it was on slot sdd.

 

I am not sure that I will use a speed test tool a 2 hour difference over a 24 hour preclear is not much, and I am guessing that the difference will not be that noticeable.  I will put the fastest drive in the parity slot.

 

Albin

Z2F0KS4Z_sdd_2013-01-05.txt

Z2F0KS4Z_sdd_new_mem_2013-01-15.txt

Z2F0KS4Z_sda_new_mem_dif_slot_2013-01-16.txt

Z1E2EQXS_sdd_new_mem_dif_slot_2013-01-16.txt

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I just finished preclearing my 3 TB drive but I am a little concerned because I have been told that 'reallocation' is a bad thing. I attached my syslog, but here is the part that made me thinking:

 

Jan 13 00:15:55 Tower preclear_disk-diff[11408]:  0 sectors were pending re-allocation before the start of the preclear.
Jan 13 00:15:55 Tower preclear_disk-diff[11408]:  16 sectors were pending re-allocation after pre-read in cycle 1 of 1.
Jan 13 00:15:55 Tower preclear_disk-diff[11408]:  0 sectors were pending re-allocation after zero of disk in cycle 1 of 1.

 

This is a new disk, and it appears there was a small region with sectors not correctly initialized.  Perhaps there had been an electrical spike that scrambled them?  I don't know.  But the zeroing phase appears to have had no problems rewriting them, so they are correct now.

 

Why not preclear the disk one more time, to reassure yourself that the disk is fine.  I really doubt you will see any further issues with this disk.

 

Ok, i cleared it one more time, I guess everything is allright now? (syslog attached)

syslog.txt

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I just finished preclearing my 3 TB drive but I am a little concerned because I have been told that 'reallocation' is a bad thing. I attached my syslog, but here is the part that made me thinking:

 

Jan 13 00:15:55 Tower preclear_disk-diff[11408]:  0 sectors were pending re-allocation before the start of the preclear.
Jan 13 00:15:55 Tower preclear_disk-diff[11408]:  16 sectors were pending re-allocation after pre-read in cycle 1 of 1.
Jan 13 00:15:55 Tower preclear_disk-diff[11408]:  0 sectors were pending re-allocation after zero of disk in cycle 1 of 1.

 

This is a new disk, and it appears there was a small region with sectors not correctly initialized.  Perhaps there had been an electrical spike that scrambled them?  I don't know.  But the zeroing phase appears to have had no problems rewriting them, so they are correct now.

 

Why not preclear the disk one more time, to reassure yourself that the disk is fine.  I really doubt you will see any further issues with this disk.

 

Ok, i cleared it one more time, I guess everything is allright now? (syslog attached)

There were no un-readable sectors this time.  ( a good thing)

 

Joe L.

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Folks, I am new to UNRAID and just bought two WD 3TB WD30EFRX from Newegg, trying to start and preclear on one and two via Screen. sdb is running while sda sits on 0% and nothing happens, I must say that sda was initialized by my Mac before but I assumed that does not matter preclear is doing raw. I have to say I have tried twice and preclear just does not start on sda. What should I try?

RedWD_sda_9309.txt

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Folks, I am new to UNRAID and just bought two WD 3TB WD30EFRX from Newegg, trying to start and preclear on one and two via Screen. sdb is running while sda sits on 0% and nothing happens, I must say that sda was initialized by my Mac before but I assumed that does not matter preclear is doing raw. I have to say I have tried twice and preclear just does not start on sda. What should I try?

 

This drive is not off to a good start, with numerous bad sectors right off the bat.  This drive wasn't drop-shipped to you, it was drop-kicked to you!  You may want to *try* to capture a SMART report, but if you can't - RMA it.  On the bright side, it's always good to find out these things *before* you trust your data to it.

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Hi everyone, please excuse me if this is a cross post but i know a lot of knowledgable folks hang out in this thread!

 

I had a red ball drive... i replaced it with a pre-cleared drive, rebuilt array, and then checked parity.  all is well on that front

 

i put the 'bad' drive back in my system, and ran the following SMART info from UNMENU.  Think there's anything really bad below?  or should i preclear and try using again?  i'm just not sure if the drive had a one time glitch or if i should throw it out.  its too old to RMA.  please let me know what you see!

 

 

SMART status Info for /dev/sdv

 

smartctl 5.40 2010-10-16 r3189 [i486-slackware-linux-gnu] (local build)

Copyright © 2002-10 by Bruce Allen, http://smartmontools.sourceforge.net

 

=== START OF INFORMATION SECTION ===

Model Family:    Western Digital Caviar Green (Adv. Format) family

Device Model:    WDC WD20EARS-00MVWB0

Serial Number:    WD-WMAZA0669236

Firmware Version: 51.0AB51

User Capacity:    2,000,398,934,016 bytes

Device is:        In smartctl database [for details use: -P show]

ATA Version is:  8

ATA Standard is:  Exact ATA specification draft version not indicated

Local Time is:    Sun Jan 20 12:28:38 2013 CST

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:  (0x84)  Offline data collection activity

              was suspended by an interrupting command from host.

              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:        (37980) 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:    ( 255) minutes.

Conveyance self-test routine

recommended polling time:    (  5) minutes.

SCT capabilities:          (0x3035)  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  199  199  051    Pre-fail  Always      -      762

  3 Spin_Up_Time            0x0027  170  162  021    Pre-fail  Always      -      6458

  4 Start_Stop_Count        0x0032  097  097  000    Old_age  Always      -      3076

  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  083  083  000    Old_age  Always      -      12999

10 Spin_Retry_Count        0x0032  100  100  000    Old_age  Always      -      0

11 Calibration_Retry_Count 0x0032  100  100  000    Old_age  Always      -      0

12 Power_Cycle_Count      0x0032  100  100  000    Old_age  Always      -      717

192 Power-Off_Retract_Count 0x0032  200  200  000    Old_age  Always      -      193

193 Load_Cycle_Count        0x0032  182  182  000    Old_age  Always      -      56442

194 Temperature_Celsius    0x0022  123  114  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      -      5

198 Offline_Uncorrectable  0x0030  200  200  000    Old_age  Offline      -      2

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      -      22

 

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  Short offline      Completed: read failure      90%    12999        2334316832

# 2  Short offline      Completed: read failure      90%    12996        2334316832

# 3  Short offline      Completed: read failure      90%    12996        2334316832

# 4  Short offline      Completed: read failure      90%    12996        2334316832

# 5  Short offline      Completed: read failure      90%    12996        2334316832

 

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.

 

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Thank you for clarifying and just for my education, preclear does not start at all, sitting at 0% progress, is that normal behavior for this script.

 

Folks, I am new to UNRAID and just bought two WD 3TB WD30EFRX from Newegg, trying to start and preclear on one and two via Screen. sdb is running while sda sits on 0% and nothing happens, I must say that sda was initialized by my Mac before but I assumed that does not matter preclear is doing raw. I have to say I have tried twice and preclear just does not start on sda. What should I try?

 

This drive is not off to a good start, with numerous bad sectors right off the bat.  This drive wasn't drop-shipped to you, it was drop-kicked to you!  You may want to *try* to capture a SMART report, but if you can't - RMA it.  On the bright side, it's always good to find out these things *before* you trust your data to it.

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Hi everyone, please excuse me if this is a cross post but i know a lot of knowledgable folks hang out in this thread!

 

I had a red ball drive... i replaced it with a pre-cleared drive, rebuilt array, and then checked parity.  all is well on that front

 

i put the 'bad' drive back in my system, and ran the following SMART info from UNMENU.  Think there's anything really bad below?  or should i preclear and try using again?  i'm just not sure if the drive had a one time glitch or if i should throw it out.  its too old to RMA.  please let me know what you see!

 

 

SMART status Info for /dev/sdv

 

smartctl 5.40 2010-10-16 r3189 [i486-slackware-linux-gnu] (local build)

Copyright © 2002-10 by Bruce Allen, http://smartmontools.sourceforge.net

 

=== START OF INFORMATION SECTION ===

Model Family:    Western Digital Caviar Green (Adv. Format) family

Device Model:    WDC WD20EARS-00MVWB0

Serial Number:    WD-WMAZA0669236

Firmware Version: 51.0AB51

User Capacity:    2,000,398,934,016 bytes

Device is:        In smartctl database [for details use: -P show]

ATA Version is:  8

ATA Standard is:  Exact ATA specification draft version not indicated

Local Time is:    Sun Jan 20 12:28:38 2013 CST

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:  (0x84)  Offline data collection activity

              was suspended by an interrupting command from host.

              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:        (37980) 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:    ( 255) minutes.

Conveyance self-test routine

recommended polling time:    (  5) minutes.

SCT capabilities:          (0x3035)  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  199  199  051    Pre-fail  Always      -      762

  3 Spin_Up_Time            0x0027  170  162  021    Pre-fail  Always      -      6458

  4 Start_Stop_Count        0x0032  097  097  000    Old_age  Always      -      3076

  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  083  083  000    Old_age  Always      -      12999

10 Spin_Retry_Count        0x0032  100  100  000    Old_age  Always      -      0

11 Calibration_Retry_Count 0x0032  100  100  000    Old_age  Always      -      0

12 Power_Cycle_Count      0x0032  100  100  000    Old_age  Always      -      717

192 Power-Off_Retract_Count 0x0032  200  200  000    Old_age  Always      -      193

193 Load_Cycle_Count        0x0032  182  182  000    Old_age  Always      -      56442

194 Temperature_Celsius    0x0022  123  114  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      -      5

198 Offline_Uncorrectable  0x0030  200  200  000    Old_age  Offline      -      2

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      -      22

 

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  Short offline      Completed: read failure      90%    12999        2334316832

# 2  Short offline      Completed: read failure      90%    12996        2334316832

# 3  Short offline      Completed: read failure      90%    12996        2334316832

# 4  Short offline      Completed: read failure      90%    12996        2334316832

# 5  Short offline      Completed: read failure      90%    12996        2334316832

 

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.

 

bump for help?

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Thank you for clarifying and just for my education, preclear does not start at all, sitting at 0% progress, is that normal behavior for this script.

 

Folks, I am new to UNRAID and just bought two WD 3TB WD30EFRX from Newegg, trying to start and preclear on one and two via Screen. sdb is running while sda sits on 0% and nothing happens, I must say that sda was initialized by my Mac before but I assumed that does not matter preclear is doing raw. I have to say I have tried twice and preclear just does not start on sda. What should I try?

 

This drive is not off to a good start, with numerous bad sectors right off the bat.  This drive wasn't drop-shipped to you, it was drop-kicked to you!  You may want to *try* to capture a SMART report, but if you can't - RMA it.  On the bright side, it's always good to find out these things *before* you trust your data to it.

not normal for it to progress slowly.  look in the syslog for errors (and clues to why it is not progressing)

 

Joe L.

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Hi everyone, please excuse me if this is a cross post but i know a lot of knowledgable folks hang out in this thread!

 

I had a red ball drive... i replaced it with a pre-cleared drive, rebuilt array, and then checked parity.  all is well on that front

 

i put the 'bad' drive back in my system, and ran the following SMART info from UNMENU.  Think there's anything really bad below?  or should i preclear and try using again?  i'm just not sure if the drive had a one time glitch or if i should throw it out.  its too old to RMA.  please let me know what you see!

 

 

SMART status Info for /dev/sdv

 

192 Power-Off_Retract_Count 0x0032  200  200  000    Old_age  Always      -      193

197 Current_Pending_Sector  0x0032  200  200  000    Old_age  Always      -      5

I'd give it a preclear cycle and see if the 5 un-readable sectors get fixed (or re-allocated)

 

I suspect a power issue though possible to be the cause of the unreadable sectors, since 193 times the disk heads were retracted in a unexpected power loss to the drive.  (of course, if the drive was in a windows box previously, and you just turned off the switch and did not stop it properly, then that might be the cause of the retractions, or if you lost power a lot in its lifetime while it was spinning)

 

Joe L.

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cool thanks joe, will initiate now.  i now realized the drive actually still has some warranty... i will do the pre clear, and if that doesn't clear the sectors, will try to rma

 

the drive was in a windows box, but i can't believe i powered down 193 times improperly!  I can believe it happened a few times, and prob a few in my unraid box, but hard to believe 193.  i have ups now on both the pc and unraid box

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Well it looks like 4 of the 5 pending sectors were reallocated, but one was not.  maybe i should try preclear again?  or just rma the drive?

 

 

========================================================================1.13

== invoked as: ./preclear_disk.sh -A -M 4 /dev/sdv

==  WDC WD20EARS-00MVWB0    WD-WMAZA0669236

== Disk /dev/sdv has been successfully precleared == with a starting sector of 64 == Ran 1 cycle == == Using :Read block size = 8225280 Bytes == Last Cycle's Pre Read Time  : 7:43:24 (71 MB/s)

== Last Cycle's Zeroing time  : 7:32:56 (73 MB/s)

== Last Cycle's Post Read Time : 14:05:37 (39 MB/s)

== Last Cycle's Total Time    : 29:23:01

==

== Total Elapsed Time 29:23:01

==

== Disk Start Temperature: 26C

==

== Current Disk Temperature: 27C,

==

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

** Changed attributes in files: /tmp/smart_start_sdv  /tmp/smart_finish_sdv

                ATTRIBUTE  NEW_VAL OLD_VAL FAILURE_THRESHOLD STATUS      RAW_VALUE

          Seek_Error_Rate =  100    200            0        ok          0

      Temperature_Celsius =  123    124            0        ok          27

No SMART attributes are FAILING_NOW

 

5 sectors were pending re-allocation before the start of the preclear.

5 sectors were pending re-allocation after pre-read in cycle 1 of 1.

0 sectors were pending re-allocation after zero of disk in cycle 1 of 1.

1 sector is pending re-allocation at the end of the preclear,

    a change of -4 in the number of sectors pending re-allocation.

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.

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

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

==

== S.M.A.R.T Initial Report for /dev/sdv ==

Disk: /dev/sdv

smartctl 5.40 2010-10-16 r3189 [i486-slackware-linux-gnu] (local build) Copyright © 2002-10 by Bruce Allen, http://smartmontools.sourceforge.net

 

=== START OF INFORMATION SECTION ===

Model Family:    Western Digital Caviar Green (Adv. Format) family

Device Model:    WDC WD20EARS-00MVWB0

Serial Number:    WD-WMAZA0669236

Firmware Version: 51.0AB51

User Capacity:    2,000,398,934,016 bytes

Device is:        In smartctl database [for details use: -P show]

ATA Version is:  8

ATA Standard is:  Exact ATA specification draft version not indicated

Local Time is:    Sun Jan 20 22:04:18 2013 CST

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: (37980) 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: ( 255) minutes.

Conveyance self-test routine

recommended polling time: (  5) minutes.

SCT capabilities:       (0x3035) 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  199  199  051    Pre-fail  Always      -      762

  3 Spin_Up_Time            0x0027  170  162  021    Pre-fail  Always      -      6458

  4 Start_Stop_Count        0x0032  097  097  000    Old_age  Always      -      3076

  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  083  083  000    Old_age  Always      -      13009

10 Spin_Retry_Count        0x0032  100  100  000    Old_age  Always      -      0

11 Calibration_Retry_Count 0x0032  100  100  000    Old_age  Always      -      0

12 Power_Cycle_Count      0x0032  100  100  000    Old_age  Always      -      717

192 Power-Off_Retract_Count 0x0032  200  200  000    Old_age  Always      -      193

193 Load_Cycle_Count        0x0032  182  182  000    Old_age  Always      -      56455

194 Temperature_Celsius    0x0022  124  114  000    Old_age  Always      -      26

196 Reallocated_Event_Count 0x0032  200  200  000    Old_age  Always      -      0

197 Current_Pending_Sector  0x0032  200  200  000    Old_age  Always      -      5

198 Offline_Uncorrectable  0x0030  200  200  000    Old_age  Offline      -      4

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      -      6

 

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%    13007        1881847353

# 2  Extended offline    Completed: read failure      90%    12999        1881847358

# 3  Short offline      Completed: read failure      90%    12999        2334316832

# 4  Short offline      Completed: read failure      90%    12996        2334316832

# 5  Short offline      Completed: read failure      90%    12996        2334316832

# 6  Short offline      Completed: read failure      90%    12996        2334316832

# 7  Short offline      Completed: read failure      90%    12996        2334316832

 

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.

==

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

 

 

 

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

==

== S.M.A.R.T Final Report for /dev/sdv

==

Disk: /dev/sdv

smartctl 5.40 2010-10-16 r3189 [i486-slackware-linux-gnu] (local build) Copyright © 2002-10 by Bruce Allen, http://smartmontools.sourceforge.net

 

=== START OF INFORMATION SECTION ===

Model Family:    Western Digital Caviar Green (Adv. Format) family

Device Model:    WDC WD20EARS-00MVWB0

Serial Number:    WD-WMAZA0669236

Firmware Version: 51.0AB51

User Capacity:    2,000,398,934,016 bytes

Device is:        In smartctl database [for details use: -P show]

ATA Version is:  8

ATA Standard is:  Exact ATA specification draft version not indicated

Local Time is:    Tue Jan 22 03:27:18 2013 CST

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: (37980) 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: ( 255) minutes.

Conveyance self-test routine

recommended polling time: (  5) minutes.

SCT capabilities:       (0x3035) 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  199  199  051    Pre-fail  Always      -      844

  3 Spin_Up_Time            0x0027  170  162  021    Pre-fail  Always      -      6458

  4 Start_Stop_Count        0x0032  097  097  000    Old_age  Always      -      3076

  5 Reallocated_Sector_Ct  0x0033  200  200  140    Pre-fail  Always      -      0

  7 Seek_Error_Rate        0x002e  100  253  000    Old_age  Always      -      0

  9 Power_On_Hours          0x0032  083  083  000    Old_age  Always      -      13037

10 Spin_Retry_Count        0x0032  100  100  000    Old_age  Always      -      0

11 Calibration_Retry_Count 0x0032  100  100  000    Old_age  Always      -      0

12 Power_Cycle_Count      0x0032  100  100  000    Old_age  Always      -      717

192 Power-Off_Retract_Count 0x0032  200  200  000    Old_age  Always      -      193

193 Load_Cycle_Count        0x0032  182  182  000    Old_age  Always      -      56455

194 Temperature_Celsius    0x0022  123  114  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      -      1

198 Offline_Uncorrectable  0x0030  200  200  000    Old_age  Offline      -      4

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      -      6

 

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%    13007        1881847353

# 2  Extended offline    Completed: read failure      90%    12999        1881847358

# 3  Short offline      Completed: read failure      90%    12999        2334316832

# 4  Short offline      Completed: read failure      90%    12996        2334316832

# 5  Short offline      Completed: read failure      90%    12996        2334316832

# 6  Short offline      Completed: read failure      90%    12996        2334316832

# 7  Short offline      Completed: read failure      90%    12996        2334316832

 

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

 

Link to comment

Hi I just cleared my 2TB drive and curious about the results. Is everything OK with it?

 

I only ran one sycle since I've been using it for 4 years without problems...

Everything looks OK, but three values look inconsistent.

 

    9 Power_On_Hours          0x0012  100  100  000    Old_age  Always      -      4505 (Misc)

  12 Power_Cycle_Count      0x0032  100  100  000    Old_age  Always      -      1273 (Misc)

192 Power-Off_Retract_Count 0x0032  097  097  000    Old_age  Always      -      3712 (Misc)

It seems to be saying that the drive has been power cycled 1273 times in the past, being spinning 4505 hours,

but that the disk heads have been retraced as a result of an unexpected loss of power 3712 times.    (as if the power connection was intermittent? )

 

Joe L.

Link to comment

Want to use a new 3Tb drive as my new Parity drive. Did 4 cycles of preclear on it. It seems ok except for the Raw_Read_Error_Rate which is at 2 while it was 0 at the start of preclear. Is this a concern?

 

start :

 

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: Vendor Specific SMART Attributes with Thresholds:

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: ID# ATTRIBUTE_NAME          FLAG    VALUE WORST THRESH TYPE      UPDATED  WHEN_FAILED RAW_VALUE

Jan 25 06:50:31 Tower preclear_disk-diff[8717]:  1 Raw_Read_Error_Rate    0x002f  200  200  051    Pre-fail  Always      -      0

Jan 25 06:50:31 Tower preclear_disk-diff[8717]:  3 Spin_Up_Time            0x0027  100  253  021    Pre-fail  Always      -      0

Jan 25 06:50:31 Tower preclear_disk-diff[8717]:  4 Start_Stop_Count        0x0032  100  100  000    Old_age  Always      -      3

Jan 25 06:50:31 Tower preclear_disk-diff[8717]:  5 Reallocated_Sector_Ct  0x0033  200  200  140    Pre-fail  Always      -      0

Jan 25 06:50:31 Tower preclear_disk-diff[8717]:  7 Seek_Error_Rate        0x002e  100  253  000    Old_age  Always      -      0

Jan 25 06:50:31 Tower preclear_disk-diff[8717]:  9 Power_On_Hours          0x0032  100  100  000    Old_age  Always      -      44

Jan 25 06:50:31 Tower preclear_disk-diff[8717]:  10 Spin_Retry_Count        0x0032  100  253  000    Old_age  Always      -      0

Jan 25 06:50:31 Tower preclear_disk-diff[8717]:  11 Calibration_Retry_Count 0x0032  100  253  000    Old_age  Always      -      0

Jan 25 06:50:31 Tower preclear_disk-diff[8717]:  12 Power_Cycle_Count      0x0032  100  100  000    Old_age  Always      -      3

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: 192 Power-Off_Retract_Count 0x0032  200  200  000    Old_age  Always      -      1

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: 193 Load_Cycle_Count        0x0032  200  200  000    Old_age  Always      -      1

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: 194 Temperature_Celsius    0x0022  125  121  000    Old_age  Always      -      25

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: 196 Reallocated_Event_Count 0x0032  200  200  000    Old_age  Always      -      0

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: 197 Current_Pending_Sector  0x0032  200  200  000    Old_age  Always      -      0

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: 198 Offline_Uncorrectable  0x0030  100  253  000    Old_age  Offline      -      0

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: 199 UDMA_CRC_Error_Count    0x0032  200  200  000    Old_age  Always      -      0

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: 200 Multi_Zone_Error_Rate  0x0008  100  253  000    Old_age  Offline      -      0

 

end :

 

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: ============================================================================

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: ==

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: == S.M.A.R.T Final Report for /dev/sdi

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: ==

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: Disk: /dev/sdi

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: smartctl 5.40 2010-10-16 r3189 [i486-slackware-linux-gnu] (local build)

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: Copyright © 2002-10 by Bruce Allen, http://smartmontools.sourceforge.net

Jan 25 06:50:31 Tower preclear_disk-diff[8717]:

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: === START OF INFORMATION SECTION ===

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: Device Model:    WDC WD30EFRX-68AX9N0

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: Serial Number:    WD-WMC1T0071253

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: Firmware Version: 80.00A80

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: User Capacity:    3,000,592,982,016 bytes

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: Device is:        Not in smartctl database [for details use: -P showall]

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: ATA Version is:  9

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: ATA Standard is:  Exact ATA specification draft version not indicated

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: Local Time is:    Fri Jan 25 06:50:30 2013 CET

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: SMART support is: Available - device has SMART capability.

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: SMART support is: Enabled

Jan 25 06:50:31 Tower preclear_disk-diff[8717]:

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: === START OF READ SMART DATA SECTION ===

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: SMART overall-health self-assessment test result: PASSED

Jan 25 06:50:31 Tower preclear_disk-diff[8717]:

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: General SMART Values:

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: Offline data collection status:  (0x00)^IOffline data collection activity

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: ^I^I^I^I^Iwas never started.

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: ^I^I^I^I^IAuto Offline Data Collection: Disabled.

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: Self-test execution status:      (  0)^IThe previous self-test routine completed

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: ^I^I^I^I^Iwithout error or no self-test has ever

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: ^I^I^I^I^Ibeen run.

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: Total time to complete Offline

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: data collection: ^I^I (41640) seconds.

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: Offline data collection

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: capabilities: ^I^I^I (0x7b) SMART execute Offline immediate.

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: ^I^I^I^I^IAuto Offline data collection on/off support.

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: ^I^I^I^I^ISuspend Offline collection upon new

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: ^I^I^I^I^Icommand.

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: ^I^I^I^I^IOffline surface scan supported.

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: ^I^I^I^I^ISelf-test supported.

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: ^I^I^I^I^IConveyance Self-test supported.

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: ^I^I^I^I^ISelective Self-test supported.

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: SMART capabilities:            (0x0003)^ISaves SMART data before entering

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: ^I^I^I^I^Ipower-saving mode.

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: ^I^I^I^I^ISupports SMART auto save timer.

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: Error logging capability:        (0x01)^IError logging supported.

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: ^I^I^I^I^IGeneral Purpose Logging supported.

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: Short self-test routine

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: recommended polling time: ^I (  2) minutes.

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: Extended self-test routine

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: recommended polling time: ^I ( 255) minutes.

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: Conveyance self-test routine

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: recommended polling time: ^I (  5) minutes.

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: SCT capabilities: ^I      (0x70bd)^ISCT Status supported.

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: ^I^I^I^I^ISCT Error Recovery Control supported.

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: ^I^I^I^I^ISCT Feature Control supported.

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: ^I^I^I^I^ISCT Data Table supported.

Jan 25 06:50:31 Tower preclear_disk-diff[8717]:

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: SMART Attributes Data Structure revision number: 16

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: Vendor Specific SMART Attributes with Thresholds:

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: ID# ATTRIBUTE_NAME          FLAG    VALUE WORST THRESH TYPE      UPDATED  WHEN_FAILED RAW_VALUE

Jan 25 06:50:31 Tower preclear_disk-diff[8717]:  1 Raw_Read_Error_Rate    0x002f  200  200  051    Pre-fail  Always      -      2

Jan 25 06:50:31 Tower preclear_disk-diff[8717]:  3 Spin_Up_Time            0x0027  100  253  021    Pre-fail  Always      -      0

Jan 25 06:50:31 Tower preclear_disk-diff[8717]:  4 Start_Stop_Count        0x0032  100  100  000    Old_age  Always      -      3

Jan 25 06:50:31 Tower preclear_disk-diff[8717]:  5 Reallocated_Sector_Ct  0x0033  200  200  140    Pre-fail  Always      -      0

Jan 25 06:50:31 Tower preclear_disk-diff[8717]:  7 Seek_Error_Rate        0x002e  100  253  000    Old_age  Always      -      0

Jan 25 06:50:31 Tower preclear_disk-diff[8717]:  9 Power_On_Hours          0x0032  100  100  000    Old_age  Always      -      150

Jan 25 06:50:31 Tower preclear_disk-diff[8717]:  10 Spin_Retry_Count        0x0032  100  253  000    Old_age  Always      -      0

Jan 25 06:50:31 Tower preclear_disk-diff[8717]:  11 Calibration_Retry_Count 0x0032  100  253  000    Old_age  Always      -      0

Jan 25 06:50:31 Tower preclear_disk-diff[8717]:  12 Power_Cycle_Count      0x0032  100  100  000    Old_age  Always      -      3

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: 192 Power-Off_Retract_Count 0x0032  200  200  000    Old_age  Always      -      1

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: 193 Load_Cycle_Count        0x0032  200  200  000    Old_age  Always      -      1

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: 194 Temperature_Celsius    0x0022  123  121  000    Old_age  Always      -      27

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: 196 Reallocated_Event_Count 0x0032  200  200  000    Old_age  Always      -      0

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: 197 Current_Pending_Sector  0x0032  200  200  000    Old_age  Always      -      0

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: 198 Offline_Uncorrectable  0x0030  100  253  000    Old_age  Offline      -      0

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: 199 UDMA_CRC_Error_Count    0x0032  200  200  000    Old_age  Always      -      0

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: 200 Multi_Zone_Error_Rate  0x0008  100  253  000    Old_age  Offline      -      0

Jan 25 06:50:31 Tower preclear_disk-diff[8717]:

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: SMART Error Log Version: 1

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: No Errors Logged

Jan 25 06:50:31 Tower preclear_disk-diff[8717]:

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: SMART Self-test log structure revision number 1

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: No self-tests have been logged.  [To run self-tests, use: smartctl -t]

Jan 25 06:50:31 Tower preclear_disk-diff[8717]:

Jan 25 06:50:31 Tower preclear_disk-diff[8717]:

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: SMART Selective self-test log data structure revision number 1

Jan 25 06:50:31 Tower preclear_disk-diff[8717]:  SPAN  MIN_LBA  MAX_LBA  CURRENT_TEST_STATUS

Jan 25 06:50:31 Tower preclear_disk-diff[8717]:    1        0        0  Not_testing

Jan 25 06:50:31 Tower preclear_disk-diff[8717]:    2        0        0  Not_testing

Jan 25 06:50:31 Tower preclear_disk-diff[8717]:    3        0        0  Not_testing

Jan 25 06:50:31 Tower preclear_disk-diff[8717]:    4        0        0  Not_testing

Jan 25 06:50:31 Tower preclear_disk-diff[8717]:    5        0        0  Not_testing

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: Selective self-test flags (0x0):

Jan 25 06:50:31 Tower preclear_disk-diff[8717]:  After scanning selected spans, do NOT read-scan remainder of disk.

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: If Selective self-test is pending on power-up, resume after 0 minute delay.

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: ==

Jan 25 06:50:31 Tower preclear_disk-diff[8717]: ============================================================================

Jan 25 06:50:31 Tower preclear_disk-diff[8717]:

Link to comment

I've been reading a bit in this topic and found the following :

 

http://lime-technology.com/forum/index.php?topic=4068.msg48756#msg48756

 

"The current "normalized" read error rate is 108, prior to the preclear, it was 117.  The worst ever measured over the lifetime of the drive was "99"  The failure threshold is "006"  If the normalized read error rate goes BELOW "006" then the drive is considered to be failing.    All drives have internal read errors.  They are all designed to re-read on an error.  As long as the normalized error rate is above the threshold, you are fine.  Nobody except the manufacturer knows how to interpret the "raw" values in the right-most column (and they don't tell anybody)"

 

So in case of my drive (post above) it would be :

 

current normalized read error rate : 200

before : 200

 

Worst value ever : 200

Threshold : 051

 

Disk is perfectly fine at this moment. I should only worry if  the current normalized value goes below 051.

 

Raw value of 2 : just ignore it as we don't know what it means (only WD knows).

 

Is this is a correct understanding?

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I've been doing pre-clears on 4TB Hitachi drives, which are understandably taking a long time ... however, as I look at the reports, I wonder why the pre-read speeds run at over 100 MB/s, where the post-read speeds run at 40-60 MB/s:

 

========================================================================1.13

== invoked as: ./preclear_disk.sh /dev/sdb

==  Hitachi HDS724040ALE640    PK2331XXXXXXXX

== Disk /dev/sdb has been successfully precleared

== with a starting sector of 1

== Ran 1 cycle

==

== Using :Read block size = 8225280 Bytes

== Last Cycle's Pre Read Time  : 9:48:16 (113 MB/s)

== Last Cycle's Zeroing time  : 8:39:42 (128 MB/s)

== Last Cycle's Post Read Time : 18:18:52 (60 MB/s)

== Last Cycle's Total Time    : 36:47:59

==

== Total Elapsed Time 36:47:59

==

== Disk Start Temperature: 31C

==

== Current Disk Temperature: 35C,

==

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

 

========================================================================1.13

== invoked as: ./preclear_disk.sh /dev/sde

==  Hitachi HDS724040ALE640    PK2331XXXXXXXX

== Disk /dev/sde has been successfully precleared

== with a starting sector of 1

== Ran 1 cycle

==

== Using :Read block size = 8225280 Bytes

== Last Cycle's Pre Read Time  : 9:55:55 (111 MB/s)

== Last Cycle's Zeroing time  : 8:41:46 (127 MB/s)

== Last Cycle's Post Read Time : 23:11:22 (47 MB/s)

== Last Cycle's Total Time    : 41:50:13

==

== Total Elapsed Time 41:50:13

==

== Disk Start Temperature: 31C

==

== Current Disk Temperature: 33C,

==

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

 

========================================================================1.13

== invoked as: ./preclear_disk.sh /dev/sdc

==  Hitachi HDS724040ALE640    PK2331XXXXXXXX

== Disk /dev/sdc has been successfully precleared

== with a starting sector of 1

== Ran 1 cycle

==

== Using :Read block size = 8225280 Bytes

== Last Cycle's Pre Read Time  : 10:02:40 (110 MB/s)

== Last Cycle's Zeroing time  : 8:58:13 (123 MB/s)

== Last Cycle's Post Read Time : 20:24:01 (54 MB/s)

== Last Cycle's Total Time    : 39:26:04

==

== Total Elapsed Time 39:26:05

==

== Disk Start Temperature: 28C

==

== Current Disk Temperature: 33C,

==

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

Some of these reports are from SATAII ports and others are from SATAIII ports ... so there's some variance in total time because of that.

 

Still, should the post-read speeds be so much slower than the pre-read speeds?

 

Thanks!

 

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I've been doing pre-clears on 4TB Hitachi drives, which are understandably taking a long time ... however, as I look at the reports, I wonder why the pre-read speeds run at over 100 MB/s, where the post-read speeds run at 40-60 MB/s:

...[snipped]...

Still, should the post-read speeds be so much slower than the pre-read speeds?

 

This should perhaps be a FAQ item!  Short answer is that the pre-read is a straight linear read, the post-read is much more complicated, with extra testing.  Better answer is provided by Joe earlier in this thread, not too long ago I think.

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I've been doing pre-clears on 4TB Hitachi drives, which are understandably taking a long time ... however, as I look at the reports, I wonder why the pre-read speeds run at over 100 MB/s, where the post-read speeds run at 40-60 MB/s:

 

Still, should the post-read speeds be so much slower than the pre-read speeds?

 

Thanks!

The pre-read throws away the contents of what is being read (sends it to /dev/null)  Its whole purpose is to let the firmware on the disk identify un-readable sectors.

 

The post-read verifies all that is being read is all zeros. (actually analyzes what is being read)

It is normal for it to take longer because of that.

 

Joe L.

Link to comment

I've been doing pre-clears on 4TB Hitachi drives, which are understandably taking a long time ... however, as I look at the reports, I wonder why the pre-read speeds run at over 100 MB/s, where the post-read speeds run at 40-60 MB/s:

 

Still, should the post-read speeds be so much slower than the pre-read speeds?

 

Thanks!

The pre-read throws away the contents of what is being read (sends it to /dev/null)  Its whole purpose is to let the firmware on the disk identify un-readable sectors.

 

The post-read verifies all that is being read is all zeros. (actually analyzes what is being read)

It is normal for it to take longer because of that.

 

Joe L.

 

Thanks Joe ... my apologies for not digging through the 110 (!!) pages of this thread.  Your tool is most helpful, and obviously very popular!

 

With 4TB drives being available, and assuming larger drives will be in our future ... are there any ways to boost the post-read speed?  This is a test rig running on an AMD Phenom 9950 X4 2.6GHz cpu and 8gb of DDR2 RAM, if that helps at all ... or is the bottleneck still the drive (and interface?) itself?

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With 4TB drives being available, and assuming larger drives will be in our future ... are there any ways to boost the post-read speed?  This is a test rig running on an AMD Phenom 9950 X4 2.6GHz cpu and 8gb of DDR2 RAM, if that helps at all ... or is the bottleneck still the drive (and interface?) itself?

The limit is mostly the drive itself... aerial density of the platters combined with their rotational speed.

 

As an example, your /dev/sdc apparently performed at an average read rate of 110MB/s

You have 4194304 MB to read. 

4194304 / 110 = 38130.0363636 seconds.

38130.0363636 seconds = 10.5916767677 hours...

 

post-read might be improved a tiny bit, but only by writing a compiled program that can perform the verification.  It will still be slower than the pre-read.  I've elected to use a shell script that invokes native linux commands so it will run on any version of unRAID.

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