Preclear plugin


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Just finished pre-clearing a 8TB Seagate Archive results:

 Cycle elapsed time: 45:07:31 | Total elapsed time: 45:07:33  
#   Step 1 of 5 - Pre-read verification:                                                  [15:03:56 @ 147 MB/s] SUCCESS    #
#   Step 2 of 5 - Zeroing the disk:                                                       [14:58:37 @ 148 MB/s] SUCCESS    #
#   Step 3 of 5 - Writing unRAID's Preclear signature:                                                          SUCCESS    #
#   Step 4 of 5 - Verifying unRAID's Preclear signature:                                                        SUCCESS    #
#   Step 5 of 5 - Post-Read verification:                                                 [15:04:50 @ 147 MB/s] SUCCESS 

 

Thought that may help you on the time.

 

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It seems as though the issues I experienced while trying to preclear a 4tb WD Red drive do not really jive up with what others experience. Most people say the page won't load and stops responding, when mine seemed to freeze up during the post-read phase the page worked fine, it sat there at 83% done with post-read for 24 hours until I canceled it. I ended up just skipping the post read when I ran it two more times. Everything seems to be functioning normally and the SMART reports look good.

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13 minutes ago, Harro said:

Just finished pre-clearing a 8TB Seagate Archive results:

 Cycle elapsed time: 45:07:31 | Total elapsed time: 45:07:33  
#   Step 1 of 5 - Pre-read verification:                                                  [15:03:56 @ 147 MB/s] SUCCESS    #
#   Step 2 of 5 - Zeroing the disk:                                                       [14:58:37 @ 148 MB/s] SUCCESS    #
#   Step 3 of 5 - Writing unRAID's Preclear signature:                                                          SUCCESS    #
#   Step 4 of 5 - Verifying unRAID's Preclear signature:                                                        SUCCESS    #
#   Step 5 of 5 - Post-Read verification:                                                 [15:04:50 @ 147 MB/s] SUCCESS 

 

Thought that may help you on the time.

 

Thanks, Mine look like yours gone post the resault  after finish , are you doing 2 preclears or jst one?

Edited by mata7
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18 hours ago, gfjardim said:


About 42 hours in that case,

############################################################################################################################
#                                                                                                                          #
#                                        unRAID Server Preclear of disk VLKKSSPZ                                           #
#                                       Cycle 1 of 1, partition start on sector 64.                                        #
#                                                                                                                          #
#                                                                                                                          #
#   Step 1 of 5 - Pre-read verification:                                                  [13:59:10 @ 158 MB/s] SUCCESS    #
#   Step 2 of 5 - Zeroing the disk:                                                       [13:49:15 @ 201 MB/s] SUCCESS    #
#   Step 3 of 5 - Writing unRAID's Preclear signature:                                                          SUCCESS    #
#   Step 4 of 5 - Verifying unRAID's Preclear signature:                                                        SUCCESS    #
#   Step 5 of 5 - Post-Read verification:                                                 [13:59:49 @ 158 MB/s] SUCCESS    #
#                                                                                                                          #
#                                                                                                                          #
#                                                                                                                          #
#                                                                                                                          #
#                                                                                                                          #
#                                                                                                                          #
#                                                                                                                          #
############################################################################################################################
#                              Cycle elapsed time: 41:48:17 | Total elapsed time: 41:48:17                                 #
############################################################################################################################

############################################################################################################################
#                                                                                                                          #
#                                               S.M.A.R.T. Status default                                                  #
#                                                                                                                          #
#                                                                                                                          #
#   ATTRIBUTE                    INITIAL  CYCLE 1  STATUS                                                                  #
#   5-Reallocated_Sector_Ct      0        0        -                                                                       #
#   9-Power_On_Hours             23       65       Up 42                                                                   #
#   194-Temperature_Celsius      32       33       Up 1                                                                    #
#   196-Reallocated_Event_Count  0        0        -                                                                       #
#   197-Current_Pending_Sector   0        0        -                                                                       #
#   198-Offline_Uncorrectable    0        0        -                                                                       #
#   199-UDMA_CRC_Error_Count     0        0        -                                                                       #
#                                                                                                                          #
#                                                                                                                          #
#                                                                                                                          #
#                                                                                                                          #
#                                                                                                                          #
############################################################################################################################
#   SMART overall-health self-assessment test result: PASSED                                                               #
############################################################################################################################

 

wow you where right on point 41:48 hours

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12 minutes ago, FrozenGamer said:

Is there a way to end after a cycle when you have told it to do 2 cycles, i am about 60 hours into a 8tb preclear and want to reboot before i wait another 65 hours.  Also should i have skipped any of the prereads etc to make it faster?

 

If you are using the plugin with unassigned devices, there should be a red X next to the pre-clear that will stop it.

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Thanks, if i press the red x after it starts cycle 2 of pre-read verification will it still show as precleared? i am at 94% on step 5 - post read.

 

Edit - answer to own question - pressed red once cycle 2 started - drive still shows as precleared - mounted it and it appears to b working fine.

 

Harro - Thanks for the reply.  It was very helpful.

Edited by FrozenGamer
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I am trying to use the latest version of the plugin on a 4TB Seagate NAS drive and the UI does not appear to be kicking off the script. It shows starting..., but nothing else happens. 

 

Script is gfjardim - 0.8.5-beta and all the settings are default. I tried running wipefs before running the preclear, but that made no difference.

 

No log is generated- show log hangs and download log returns a 0 byte zip. I see no process running when I grep for preclear.

 

Update 4/6: Looks like a reboot fixed whatever the problem was.

Edited by ssb201
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  • 2 weeks later...
Apr 20 07:54:59 tower root: error: plugins/preclear.disk/Preclear.php: missing csrf_token
Apr 20 07:55:09 tower root: error: plugins/preclear.disk/Preclear.php: missing csrf_token
Apr 20 07:55:19 tower root: error: plugins/preclear.disk/Preclear.php: missing csrf_token
Apr 20 07:55:29 tower root: error: plugins/preclear.disk/Preclear.php: missing csrf_token
Apr 20 07:55:39 tower root: error: plugins/preclear.disk/Preclear.php: missing csrf_token

Unraid 6.3.3 with preclear plugin 03/31/2017 and I uninstalled and reinstalled the plugin yet am still getting these errors.  Server is behind the great firewall of China if that matters...

 

drchina1-diagnostics-20170420-0807.zip

  • Upvote 1
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I just picked up an external 5-bay disk enclosure I'd like to add to my 24-bay server.  I have a bunch of smaller disks that came out of my unRAID array that I had previously updated and want to use in the external enclosure.  I have been attempting to run a preclear on the drives and it either fails or runs painfully slow.  I'm using the preclear plug-in on unRAID Server Pro version 6.3.2 with a 24-disk array (including a single parity drive and a cache drive).  I have tried using both current versions of the plug-in.

 

Do I even need to run a preclear on the drives?  My main concern is that they still contain data that would be a duplicate of what's already on the replacement drives.  If I add them to the array I assume that it will automatically rebuild parity with the data that's on the drives.  I suppose I could stop the parity rebuild and then delete the data manually, but chances are I'd have to rebuild parity again from scratch since it's unlikely I could halt it in time.  I'm trying to figure out the best approach to reintroducing drives with existing data that I would like to clear.

 

Can I just run a low-level format and then insert them into the array without having to do another pre-clear?

Edited by captain_video
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16 minutes ago, captain_video said:

If I add them to the array I assume that it will automatically rebuild parity with the data that's on the drives.

Only if you do a new config. If you simply add them, unraid will clear them before allowing them to be formatted.

 

Are you sure they are all perfectly healthy? Good smart reports, etc? You really do not want drives in your server with health issues, and failing to preclear and / or running slowly doesn't give me any warm'n'fuzzies about the health of the drives.

 

20 minutes ago, captain_video said:

I just picked up an external 5-bay disk enclosure I'd like to add to my 24-bay server.

How is it connected? If the total bandwidth to the enclosure isn't good, you will be slowing down parity checks or rebuilds to the point of being unusable.

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16 minutes ago, captain_video said:

I just picked up an external 5-bay disk enclosure I'd like to add to my 24-bay server.  I have a bunch of smaller disks that came out of my unRAID array that I had previously updated and want to use in the external enclosure.  I have been attempting to run a preclear on the drives and it either fails or runs painfully slow.  I'm using the preclear plug-in on unRAID Server Pro version 6.3.2 with a 24-disk array (including a single parity drive and a cache drive).  I have tried using both current versions of the plug-in.

 

Do I even need to run a preclear on the drives?  My main concern is that they still contain data that would be a duplicate of what's already on the replacement drives.  If I add them to the array I assume that it will automatically rebuild parity with the data that's on the drives.  I suppose I could stop the parity rebuild and then delete the data manually, but chances are I'd have to rebuild parity again from scratch since it's unlikely I could halt it in time.  I'm trying to figure out the best approach to reintroducing drives with existing data that I would like to clear.

 

Can I just run a low-level format and then insert them into the array without having to do another pre-clear?

If there is only one port connecting the 5 externals to the main server, then of course it is going to be very slow because the 5 disks must share the single port. This will also affect parity checks and rebuilds since all disks are used at the same time, and if they have to share a port everything will be waiting on them.

 

unRAID will not rebuild parity unless you make it do so. Instead, it will insist on clearing any disks you add to the array if they aren't already clear.

 

Deleting files or formatting will not help in any way, since those operations will not result in a clear disk. A disk must be all zeros when it is added to the parity array so parity will remain valid. Disks that have all the files deleted or that have been formatted are not all zeros. So unRAID will clear them if you don't.

 

It would also be possible to set a New Config with the disks in whatever state, and let unRAID rebuild parity and format them.

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The enclosure is a Supermicro CSE-M35T-1B 5-drive bay that has five discreet SATA inputs.  I'm just sitting the enclosure on top of the server chassis and using extension cables for the power inputs and 36-inch SATA cables for the signal connections.  My server board uses three Supermicro AOC-SASLP-MV8 8-port SATA controllers for the drives in the internal array and parity drive and a single dual-port SATA III controller (not currently connected to anything).  The motherboard has six onboard SATA III ports, one of which is currently used for a 250GB SSD cache drive.  I plan to use the five unused onboard SATA ports to connect directly to the enclosure so speed shouldn't be an issue.

 

Doesn't a low level format write all zeroes to the disk?  I'm using the HDD LLF Low Level Format tool from this site:

 

http://hddguru.com/software/

 

The drives were healthy and working fine before I pulled them from the array.  I only replaced them with larger drives for increased capacity.

Edited by captain_video
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Hmmm, OK.  On a side note, I reinstalled one of the drives that failed the preclear attempt and it treated it like a new precleared drive and rebuilt the data from parity.  The drive had been in the array previously in a different location and I replaced it with a new, larger drive.  After it rebuilt the data on the new drive from parity I attempted to perform a preclear on the old drive to write all zeroes to it.  The preclear got hung up and subsequent attempts to preclear it failed.  I took a risk and swapped out the old drive with a smaller one in the array to see what would happen. I figured if it tried to rerun a parity check I'd just stop the array and replace the old drive and restore the original configuration and the perform a new parity check.  Instead, it treated the old drive as a precleared drive and restored the data, even though the drive had data from it's former location.  I assume the preclear wiped the MBR so it saw it as a blank drive and rebuilt the data from the old drive using parity.

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2 hours ago, captain_video said:

Hmmm, OK.  On a side note, I reinstalled one of the drives that failed the preclear attempt and it treated it like a new precleared drive and rebuilt the data from parity.  The drive had been in the array previously in a different location and I replaced it with a new, larger drive.  After it rebuilt the data on the new drive from parity I attempted to perform a preclear on the old drive to write all zeroes to it.  The preclear got hung up and subsequent attempts to preclear it failed.  I took a risk and swapped out the old drive with a smaller one in the array to see what would happen. I figured if it tried to rerun a parity check I'd just stop the array and replace the old drive and restore the original configuration and the perform a new parity check.  Instead, it treated the old drive as a precleared drive and restored the data, even though the drive had data from it's former location.  I assume the preclear wiped the MBR so it saw it as a blank drive and rebuilt the data from the old drive using parity.

Rebuilds absolutely don't care whether a drive is precleared or cleared or anything else about what is already on the disk, since it is going to completely overwrite the disk with the rebuild.

 

The only time a clear disk is required is when adding a disk to a new slot in an array that already has parity. This is so parity will remain valid. Since a clear disk is all zeros, adding a clear disk to a new slot will have no effect on parity.

 

The only reason to preclear a replacement is to test the disk.

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