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Preclear plugin

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Just now, gfjardim said:

🤔 All in the same port? These are drives that you're planning to shuck?

Yup, stay in enclosure (semi open so no heat issues) until tested and precleared then breakout and replace smaller drives in array. Been doing it for a good fewe weeks now and no probs till recently.

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5 minutes ago, superloopy1 said:

Yup, stay in enclosure (semi open so no heat issues) until tested and precleared then breakout and replace smaller drives in array. Been doing it for a good fewe weeks now and no probs till recently.

Maybe you got a bad USB/SATA bridge controller. Try connecting it into the controller of another hard drive you've already shucked.

I'm new at unraid, so bear with me for being noobish.

I'm folling Spaceinvader One's basic tutorial, and I'm at the PreClear part, where I've run the SMART test, the extended one, and now I want to preclear the SSD, but it says this:

Quote

The disk '/dev/sdd' is part of unRAID's array, or is assigned as a cache device. Please choose another one from below: ==================================== Disks not assigned to the unRAID array (potential candidates for clearing) ======================================== /dev/sdb = ST4000DM005-2DP166_ZDH3H5R7 /dev/sdc = ST31000528AS_9VP7H8ZK

I did have it assigned as the cache drive, but no longer, it's not mounted, and the array is not running.
Can someone tell me what to do in order to preclear it?

I have a 1 TB and a 4 TB drive that is currently running the same SMART test, but it takes more time, the one at 1 TB is at 50 %, and the 4 TB is at 20 %.

Will I have the same issue with those 2 drives? They were assigned in the array, but is no longer, the same as the SSD.

 

Let me know if you need any other information.

  • Author
7 minutes ago, Nanobug said:

I'm new at unraid, so bear with me for being noobish.

I'm folling Spaceinvader One's basic tutorial, and I'm at the PreClear part, where I've run the SMART test, the extended one, and now I want to preclear the SSD, but it says this:

I did have it assigned as the cache drive, but no longer, it's not mounted, and the array is not running.
Can someone tell me what to do in order to preclear it?

I have a 1 TB and a 4 TB drive that is currently running the same SMART test, but it takes more time, the one at 1 TB is at 50 %, and the 4 TB is at 20 %.

Will I have the same issue with those 2 drives? They were assigned in the array, but is no longer, the same as the SSD.

 

Let me know if you need any other information.

After remove the drive from the array, you have to start the array again to remove any references of it.

I please need some help. I have a mix of brand new Seagate ST2000 drives and identical drives that were in a previous trial array where they worked fine. Now they're all failing preclear at the post read. All but one of them (S/N ending in 6381) have no SMART errors and I can't see anything specific in the log files that indicates an actual failure. The Post-Read process is simply terminating with "your drive is not zeroed."

 

To make things more confusing other drives, but not this particular ST2000 model, have precleared just fine on the exact same hardware and Unraid USB configuration. I'm using the classic supported LSI/Avago 9211-8i controller running IT firmware.

 

This is running the latest version of preclear with the default script on Unraid 6.8.2. I'm wondering if everything worked before because it was an older version of both?

 

I've attached the report and log for the serial number ending in 1033. It shows the SMART status is fine. The reports/logs are identical for all the other "failing" drives (except S/N 6381 which may have a legit problem). I've also attached the Unraid diagnostics ZIP and included a few screenshots.

 

Does anyone have any ideas or suggestions? Any help would be greatly appreciated!

 

preclear post read fails.jpg

preclear hdd smart status.jpg

preclear log failure sn1033.txt preclear report failure sn1033.txt tower-diagnostics-20200305-0916.zip

Edited by dev_guy

8 minutes ago, dev_guy said:

The Post-Read process is simply terminating with "your drive is not zeroed."

Have you done memtest? Bad RAM has caused this in the past, including for me.

35 minutes ago, gfjardim said:

After remove the drive from the array, you have to start the array again to remove any references of it.

Do you have a noobs guide for that?

Because I can't stsart it after I've removed/unassigned it.

  • Author
5 minutes ago, trurl said:

Have you done memtest? Bad RAM has caused this in the past, including for me.

For that amount of disks failing preclear, my guess is indeed memory errors, but he got disks dropping out too like "/dev/sde" and "/dev/sdg".

  • Author
5 minutes ago, Nanobug said:

Do you have a noobs guide for that?

Because I can't stsart it after I've removed/unassigned it.

Array drives aren't supposed to be removed like that; or you replace the drive with another with the same/larger capacity, or you have to invalidate the parity to do that. What dou you want to accomplish?

Just now, gfjardim said:

Array drives aren't supposed to be removed like that; or you replace the drive with another with the same/larger capacity, or you have to invalidate the parity to do that. What dou you want to accomplish?

I'm following Spaceinvader One's basic tutorials since I'm completely new at unraid, and I'm preclearing the drives. And I can't do it for the SSD/cache drive.

  • Author
4 minutes ago, Nanobug said:

I'm following Spaceinvader One's basic tutorials since I'm completely new at unraid, and I'm preclearing the drives. And I can't do it for the SSD/cache drive.

Do you already created your parity?

I'm using no parity atm. I don't have a spare drive. I'm going to upgrade capacity and add a parity drive later on.

15 minutes ago, trurl said:

Have you done memtest? Bad RAM has caused this in the past, including for me.

I have not. That wouldn't explain why other drives have precleared on the same hardware but it's a good suggestion. This is a different motherboard and RAM than I had the earlier array running on. You would think, however, if I had bad RAM it would eventually crash Unraid and the entire machine. Still, it's worth a try.

  • Author
54 minutes ago, Nanobug said:

I'm using no parity atm. I don't have a spare drive. I'm going to upgrade capacity and add a parity drive later on.

So you will preclear an empty drive and then add it to the array? Empty the contents another drive into the array, preclear this one and then add it too?

Edited by gfjardim

17 minutes ago, gfjardim said:

So you will preclear an empty drive and then add it to the array? Empty the contents another drive into the array, preclear this one and then add it too?

It's not empty. It was running with a Windows 10 Pro before. So I just wanna clear it completely, and then use it, or whatever makes more sense.

1 hour ago, dev_guy said:

You would think, however, if I had bad RAM it would eventually crash Unraid and the entire machine. Still, it's worth a try.

You might think that... The thing about bad RAM is that you never know exactly how it may fail.  It may be a single bit error at a single location.  It may be an addressing fault (accessing the same physical bits at more than one location).  It may be an error across a block of addresses.  It may crash unRAID or it may remain invisible.  The same goes for other operating sytems such as Windows.  RAM can also go bad after months or years of rock-solid service.  I would always recommend at least three complete passes of Memtest, and even then that may not catch everything.  I would also recommend anyone to run it maybe once a year if they have some server down time. 

  • Author
4 hours ago, Nanobug said:

It's not empty. It was running with a Windows 10 Pro before. So I just wanna clear it completely, and then use it, or whatever makes more sense.

You have to go to Tools > New Config, set Preserve current assignments to None, check Yes I want to do this and then click Apply.

5 hours ago, S80_UK said:

You might think that... The thing about bad RAM is that you never know exactly how it may fail. 

I agree memory problems can be elusive. I've been running Memtest for the last 6 hours with no errors so far. I'll let it run overnight. I think a more likely explanation is there's some weird incompatibility with the current version of Preclear (or the script) that's not compatible with these drives at least on that hardware. They're 2.5" drives which I suspect not many Unraid users use. The target hardware is a 1U shallow rack Xeon Supermicro server with ECC RAM but I'm doing the preclear offline on a different system where all the supposed "failures" occurred.

  • Author
48 minutes ago, dev_guy said:

I agree memory problems can be elusive. I've been running Memtest for the last 6 hours with no errors so far. I'll let it run overnight. I think a more likely explanation is there's some weird incompatibility with the current version of Preclear (or the script) that's not compatible with these drives at least on that hardware. They're 2.5" drives which I suspect not many Unraid users use. The target hardware is a 1U shallow rack Xeon Supermicro server with ECC RAM but I'm doing the preclear offline on a different system where all the supposed "failures" occurred.

There are no incompatibilities between the script and your hard drives; or the data stream became corrupted before it was written, or it became corrupted after it was read, or your system produces zero filled data streams that aren't composed only by zeros. Many things can corrupt data, like bad memories, bad PSU, bad cables, bad HBA. The script relies on applications widely used around the world, like dd for read and cmp for comparison. And no incompatibility can lead to hard drives being dropped by the HBA, only a driver or a hardware problem can drop drives like that. I'm not defending the script by itself, I'm alerting you that your system may have more serious issues than it appear to have.

1 hour ago, gfjardim said:

There are no incompatibilities between the script and your hard drives; or the data stream became corrupted before it was written, or it became corrupted after it was read, or your system produces zero filled data streams that aren't composed only by zeros. Many things can corrupt data, like bad memories, bad PSU, bad cables, bad HBA. The script relies on applications widely used around the world, like dd for read and cmp for comparison. And no incompatibility can lead to hard drives being dropped by the HBA, only a driver or a hardware problem can drop drives like that. I'm not defending the script by itself, I'm alerting you that your system may have more serious issues than it appear to have.

Thank you for the reply and also the suggestions from S80_UK and Trurl. I ran HTOP with columns for I/O enabled and noticed DD and CMP were being used. And I agree those by themselves should not be an issue. I am currently trying to preclear the drives again on different hardware.

 

I ran HTOP because Unraid was reporting 100% CPU doing the preclear on 7 drives at the same time. But HTOP was only reporting around 50% total CPU usage so I'm assuming Unraid somehow has that wrong in the dashboard (at least for my configuration). But I would assume, even if the preclear process is limited by 100% CPU, it still should not cause false failures.

 

I'll report what happens on the new hardware when the new batch of preclears complete. Thanks again!

19 hours ago, trurl said:

Have you done memtest? Bad RAM has caused this in the past, including for me.

Thank you Trurl! The system I was doing the preclear on DID have bad RAM! It has 32GB or RAM so it took a while for it to show up in the memory test. So thanks for that tip! And, likewise, the same drives precleared successfully on different hardware.

 

The drive that had logged a SMART error for a pending sector needed to be precleared with pre-read disabled so it would not abort before it ever got to the zero phase. During the zero phase the pending sector was recovered.

 

Thanks also to S80_UK and Gfjardim for their input. Indirectly preclear helped me find bad RAM rather than bad drives.

 

A question to gfjardim or anyone else: Is the pre-read designed to cause a preclear to abort early if a drive has problems? I suspect this is documented elsewhere in this 109 page thread, but it seems to fail drives with "soft" errors unless you disable the pre-read and then the pending sector is recovered during the zero phase? Someone using the default settings might assume an expensive hard drive is defective when, in reality, it's not.

 

  • Author
26 minutes ago, dev_guy said:

Thanks also to S80_UK and Gfjardim for their input. Indirectly preclear helped me find bad RAM rather than bad drives.

 

A question to gfjardim or anyone else: Is the pre-read designed to cause a preclear to abort early if a drive has problems? I suspect this is documented elsewhere in this 109 page thread, but it seems to fail drives with "soft" errors unless you disable the pre-read and then the pending sector is recovered during the zero phase? Someone using the default settings might assume an expensive hard drive is defective when, in reality, it's not.

 

 

Glad it helped both ways!

 

Pre-read will abort if there is any read errors, including those generated by pending sectors. The problem here is documentation IMO, because the pending sector will show in the log but the user don't have any indication of what to do. Maybe more Q/A entries on the OP should help Thanks for pointing out.

Hello, first time using Preclear (well, first time using unraid). I am preclearing a disk (WD RED 4TB) and I was wondering if this is normal (the decrease in speed, now it is at 98 % with a speed of 87 MB/s):

 

Mar 07 13:35:27 preclear_disk_WD-WCC7K5VD2F2P_28187: Pre-Read: progress - 10% read @ 181 MB/s
Mar 07 14:12:22 preclear_disk_WD-WCC7K5VD2F2P_28187: Pre-Read: progress - 20% read @ 177 MB/s
Mar 07 14:50:27 preclear_disk_WD-WCC7K5VD2F2P_28187: Pre-Read: progress - 30% read @ 171 MB/s
Mar 07 15:30:10 preclear_disk_WD-WCC7K5VD2F2P_28187: Pre-Read: progress - 40% read @ 163 MB/s
Mar 07 16:12:06 preclear_disk_WD-WCC7K5VD2F2P_28187: Pre-Read: progress - 50% read @ 153 MB/s
Mar 07 16:56:43 preclear_disk_WD-WCC7K5VD2F2P_28187: Pre-Read: progress - 60% read @ 145 MB/s
Mar 07 17:44:45 preclear_disk_WD-WCC7K5VD2F2P_28187: Pre-Read: progress - 70% read @ 133 MB/s
Mar 07 18:37:33 preclear_disk_WD-WCC7K5VD2F2P_28187: Pre-Read: progress - 80% read @ 119 MB/s
Mar 07 19:36:42 preclear_disk_WD-WCC7K5VD2F2P_28187: Pre-Read: progress - 90% read @ 104 MB/s

if this is normal can somebody explain why? Thank you!

 

7 minutes ago, jorge16 said:

Hello, first time using Preclear (well, first time using unraid). I am preclearing a disk (WD RED 4TB) and I was wondering if this is normal (the decrease in speed, now it is at 98 % with a speed of 87 MB/s):

 


Mar 07 13:35:27 preclear_disk_WD-WCC7K5VD2F2P_28187: Pre-Read: progress - 10% read @ 181 MB/s
Mar 07 14:12:22 preclear_disk_WD-WCC7K5VD2F2P_28187: Pre-Read: progress - 20% read @ 177 MB/s
Mar 07 14:50:27 preclear_disk_WD-WCC7K5VD2F2P_28187: Pre-Read: progress - 30% read @ 171 MB/s
Mar 07 15:30:10 preclear_disk_WD-WCC7K5VD2F2P_28187: Pre-Read: progress - 40% read @ 163 MB/s
Mar 07 16:12:06 preclear_disk_WD-WCC7K5VD2F2P_28187: Pre-Read: progress - 50% read @ 153 MB/s
Mar 07 16:56:43 preclear_disk_WD-WCC7K5VD2F2P_28187: Pre-Read: progress - 60% read @ 145 MB/s
Mar 07 17:44:45 preclear_disk_WD-WCC7K5VD2F2P_28187: Pre-Read: progress - 70% read @ 133 MB/s
Mar 07 18:37:33 preclear_disk_WD-WCC7K5VD2F2P_28187: Pre-Read: progress - 80% read @ 119 MB/s
Mar 07 19:36:42 preclear_disk_WD-WCC7K5VD2F2P_28187: Pre-Read: progress - 90% read @ 104 MB/s

if this is normal can somebody explain why? Thank you!

 

If it's a spinning drive (mechanical) it's normal.
Imagine it's a CD/DVD disk, on the edge it will access more data, because the circle is larger, because it has more area to read/write from, the closer it gets to the center, it will have less, because the circle is smaller.

Edited by Nanobug

2 minutes ago, jorge16 said:

Hello, first time using Preclear (well, first time using unraid). I am preclearing a disk (WD RED 4TB) and I was wondering if this is normal (the decrease in speed, now it is at 98 % with a speed of 87 MB/s):

 


Mar 07 13:35:27 preclear_disk_WD-WCC7K5VD2F2P_28187: Pre-Read: progress - 10% read @ 181 MB/s
Mar 07 14:12:22 preclear_disk_WD-WCC7K5VD2F2P_28187: Pre-Read: progress - 20% read @ 177 MB/s
Mar 07 14:50:27 preclear_disk_WD-WCC7K5VD2F2P_28187: Pre-Read: progress - 30% read @ 171 MB/s
Mar 07 15:30:10 preclear_disk_WD-WCC7K5VD2F2P_28187: Pre-Read: progress - 40% read @ 163 MB/s
Mar 07 16:12:06 preclear_disk_WD-WCC7K5VD2F2P_28187: Pre-Read: progress - 50% read @ 153 MB/s
Mar 07 16:56:43 preclear_disk_WD-WCC7K5VD2F2P_28187: Pre-Read: progress - 60% read @ 145 MB/s
Mar 07 17:44:45 preclear_disk_WD-WCC7K5VD2F2P_28187: Pre-Read: progress - 70% read @ 133 MB/s
Mar 07 18:37:33 preclear_disk_WD-WCC7K5VD2F2P_28187: Pre-Read: progress - 80% read @ 119 MB/s
Mar 07 19:36:42 preclear_disk_WD-WCC7K5VD2F2P_28187: Pre-Read: progress - 90% read @ 104 MB/s

if this is normal can somebody explain why? Thank you!

 

The inner "cylinders" have less data in them (shorter in circumference) but the rotation rate is the same. It starts with the outer (longer, more data) and works towards the inner (shorter, less data). So the data rate will be less as it works through the whole disk.

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