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Unofficial Faster Preclear

Featured Replies

I've just precleared a WD 6TB using the script and it's giving me an 'HPA?' entry against the drive when viewed via unmenu. A bit out of the loop here but is this anything to get concerned about? Drive has been allocated as parity for the array and has been precleared 3 cycles and parity checked against existing data drives which are still at 4TB. Am i likely to see any problems as i migrate drives to 6TB if there actually IS an hpa present or is this a known issue?

 

Unmenu is old and doesn't recognize the new larger drives from what everyone with a new larger drive has experienced. It shouldn't be a problem.

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I've just precleared a WD 6TB using the script and it's giving me an 'HPA?' entry against the drive when viewed via unmenu. A bit out of the loop here but is this anything to get concerned about? Drive has been allocated as parity for the array and has been precleared 3 cycles and parity checked against existing data drives which are still at 4TB. Am i likely to see any problems as i migrate drives to 6TB if there actually IS an hpa present or is this a known issue?

 

Unmenu is old and doesn't recognize the new larger drives from what everyone with a new larger drive has experienced. It shouldn't be a problem.

Good to hear ... thanks!

  • 3 weeks later...

I've just run a (old/slow) preclear on one 2TB drive (I can check when I get home but it took about 25 hours).

 

I have to format it and copy data off an identical drive from my old server at which point I'll be pre-clearing and installing the second drive in my new unRAID server. I'd love to do a comparison of the two preclears!

 

Then I also have to run a triple preclear on a new HTGS Nas 4TB drive when it arrives from Newegg (to be my parity drive) so I'd love to get those 3 runs done faster as well.

 

I'm a complete neophyte at unRAID, so I'd appreciate some clear instructions (a "Faster preclear for dummies").

 

Running V6-64bit.

 

Thanks!

  • Author

Suggest you use the supported preclear if you've never done it before.

 

After you understand the process, look at the first post in this thread. Download the zip file. There is a readme file inside that provides details.

 

 

Well as I said, I've already run one (though I think that hardly qualifies me as an expert).

 

I guess I'll have a look at the readme  when I get home and see how it differs.

 

 

hey fellow unRaiders... so i've successfully precleared 4 drives last week but my 5th didnt make it just errored out..

 

it was almost done, over 50% on the 3rd cycle. i'm not savvy enough to know what the log is saying. any help will be appreciated.

 

========================================================================1.15b

== invoked as: ./preclear_bjp.sh -r 65536 -w 65536 -b 2000 -f -A -c 3 /dev/sdf

==

== Disk /dev/sdf has NOT been successfully precleared

== Postread detected un-expected non-zero bytes on disk==

== Ran 3 cycles

==

== Using :Read block size = 65536 Bytes

== Last Cycle's Pre Read Time  : 7:10:34 (96 MB/s)

== Last Cycle's Zeroing time  : 6:38:47 (104 MB/s)

== Last Cycle's Post Read Time : 0:33:14 (1253 MB/s)

== Last Cycle's Total Time    : 7:13:00

==

== Total Elapsed Time 28:47:37

==

==

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

No SMART attributes are FAILING_NOW

 

 

    the number of sectors pending re-allocation did not change.

    the number of sectors re-allocated did not change.

SMART overall-health status = 

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

 

 

 

  • Author

Did you properly install the correct version of the readvz file?

I believe I did.. I'm on unRaid ver 5.6

looked and saw i didnt :/ sorry about that dont know how i missed it.. it worked fine with the last 4 drives..

 

guess i'll start it over..

 

thx for the tip/help..

 

ok not sure what happened this time.. it didnt create a log file in the preclear_reports folder here's what i copied from the putty screen

 

 

================================================================== 1.15b

=                unRAID server Pre-Clear disk /dev/sdf

=              cycle 2 of 3, partition start on sector 1

=

= 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 - Verifying if the MBR is cleared.              DONE

=

Elapsed Time:  22:48:29

========================================================================1.15b

==

== SORRY: Disk /dev/sdf MBR could NOT be precleared

==

== out4= 00000

== out5= 00000

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

dd: opening `/dev/sdf': No such device or address

0000000

root@FatJoe:/boot#

 

and attached is whats on the unMenu screen

 

is it just a bad disk or is something else wrong?

 

thx.

Capture.JPG.15900ce9ba104097e58589b3a53340a9.JPG

  • Author

I do not know.

 

Looks like the drive dropped off line at the very end.

should i add it to the array? or put it into another slot and try to preclear again?

  • Author

You can test it for a preclear signature.

 

Any idea why it dropped suddenly at the end?

 

Timing is too coincidental. Might indicate a problem with the drive. Not sure.

i'm not sure..

one weird thing is that its identifier device ID swapped with another drive :|  one that's been running since last week and has data on it..

 

i'm copying some data to it right now to see if it may error out?

 

also unfortunately i added it to the array before i saw your msg about checking the preclear sig because unmenu "MyMain" indicated it was ready to be added. that array formatted it and in a few minutes i was added data to it..

 

 

 

 

  • Author

Suggest you capture a syslog and start a new thread. Your issues may have started while doing a preclear, but it seems some funky things are happening on your server that are not due to any issue with the preclear script.

Ok thx

  • 2 months later...

dumb question, if I put preclear into /boot/preclear as opposed to just /boot, does it still work the same?

 

I ask because I see this:

 

= 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 - Verifying if the MBR is cleared.              DONE
= Post-Read in progress: 99% complete.
(  5,000,839,372,800  of  5,000,981,078,016  bytes read )
Disk Temperature: 40C, Elapsed Time:  22:26:14
./preclear_bjp.sh: line 1186: post_read_err: command not found






================================================================== 1.15b
=                unRAID server Pre-Clear disk /dev/sdb
=               cycle 1 of 1, partition start on sector 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 - Verifying if the MBR is cleared.              DONE
= Disk Post-Clear-Read completed                                DONE
Disk Temperature: 40C, Elapsed Time:  22:26:15
========================================================================1.15b
== TOSHIBAMD04ACA500   Y4M5K0PYFS9A
== Disk /dev/sdb has NOT been precleared successfully
== ./preclear_bjp.sh: line 1182: /boot/readvz: No such file or directory ./preclear_bjp.sh: line 1182: /boot/readvz: No such file or directory ./preclear_bjp.sh: line 1182: /boot/readvz: No such file or directory ./preclear_bjp.sh: line 1182: /boot/readvz: No such file or directory ./preclear_bjp.sh: line 1182: /boot/readvz: No such file or directory ./preclear_bjp.sh: line 1182: /boot/readvz: No such file or directory ./preclear_bjp.sh: line 1182: /boot/readvz: No such file or directory ./preclear_bjp.sh: line 1182: /boot/readvz: No such file or directory ./preclear_bjp.sh: line 1182: /boot/readvz: No such file or directory ./preclear_bjp.sh: line 1182: /boot/readvz: No such file or directory
============================================================================
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 1.
0 sectors were pending re-allocation after zero of disk in cycle 1 of 1.
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.

 

I mean the message is fairly clear that it failed, but the question is, did it?

 

It is a 5TB drive and it completed in 24hours, so it did seem fast, but before moving the files to /boot and starting again, I thought it is worth asking.

thanks

  • Author

Did you copy readvz to the root of the flash?

No,  everything in boot/preclear, force of habit

  • Author

No,  everything in boot/preclear, force of habit

 

Would be very easy to edit the script to change the directory. But otherwise you need to follow the directions.

So run it again  with the right directories?  Without that I assume preclear didn't really do its job?

Answered my own question,  put files where specified and now running at the pace expected

  • 2 weeks later...

Without reading everything, is the faster preclear all good?

  • 4 weeks later...

Yes,  I was doing it like I do normal preclear,  but that is not what the directions say.  When I did as told,  it worked as expected.

  • 1 month later...

Thank you so much for sharing this.  Just bought two 5TB drives, unfortunately didn't see this post until first one started the preclear.  here are the stat differences.  Saves me almost 40 hours on 3 preclear cycles!

 

Old Preclear

== Ran 3 cycles

==

== Using :Read block size = 1000448 Bytes

== Last Cycle's Pre Read Time  : 13:05:13 (106 MB/s)

== Last Cycle's Zeroing time  : 9:10:29 (151 MB/s)

== Last Cycle's Post Read Time : 20:36:10 (67 MB/s)

== Last Cycle's Total Time    : 29:47:40

==

== Total Elapsed Time 103:27:26

 

Faster Preclear

== Ran 3 cycles

==

== Using :Read block size = 1000448 Bytes

== Last Cycle's Pre Read Time  : 10:20:50 (134 MB/s)

== Last Cycle's Zeroing time  : 8:10:20 (169 MB/s)

== Last Cycle's Post Read Time : 10:26:13 (133 MB/s)

== Last Cycle's Total Time    : 18:37:42

==

== Total Elapsed Time 66:16:13

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