Preclear plugin


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8 hours ago, wepee said:

Yes, I am installiing a fresh copy of unRAID on a Sandisk flash drive 8GB usb 2.0 thumb drive.

 

I think I should not be doing another round of preclear, since the last preclear operation has completely successfully,

 

unRAID will be noticed it, once I get the unRAID server up and running, right?

 

I mean it will recognize the hard disks since it has a preclear signature written on them from the last preclear operation, right?

Thanks for your help so far........

 

I reinstalled my unRAID server on a Sandisk thumb drive, after my previous Kingmax thumb drive was dead.

 

I reinstalled the preclear plugin.

 

Preclear plugin did not recognize my hard disks were previously completed preclear test.

If it was able to detect and recognize, there should be a round "+" little icon appear on 

the hdd. But I did not see any.

 

That is totally normal right?

Edited by wepee
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Hi all,

Thanks for this great plugin. I noticed something in the logs when I started a new pre-clear...

 

Quote

Mar 18 20:46:08 preclear_disk_WD-WX31D49KSHC5_15553: Preclear Disk Version: 1.0.14
Mar 18 20:46:08 preclear_disk_WD-WX31D49KSHC5_15553: Disk /dev/sdj is a SSD, disabling head stress test.
Mar 18 20:46:08 preclear_disk_WD-WX31D49KSHC5_15553: S.M.A.R.T. info type: default
Mar 18 20:46:08 preclear_disk_WD-WX31D49KSHC5_15553: S.M.A.R.T. attrs type: default
Mar 18 20:46:08 preclear_disk_WD-WX31D49KSHC5_15553: Disk size: 6001175126016
Mar 18 20:46:08 preclear_disk_WD-WX31D49KSHC5_15553: Disk blocks: 1465130646
Mar 18 20:46:08 preclear_disk_WD-WX31D49KSHC5_15553: Blocks (512 bytes): 11721045168
Mar 18 20:46:08 preclear_disk_WD-WX31D49KSHC5_15553: Block size: 4096
Mar 18 20:46:08 preclear_disk_WD-WX31D49KSHC5_15553: Start sector: 0

 

I'm wondering why it thinks this disk (a WD red 6tb) is an SSD. Should I adjust something to do the head stress test that it has disabled?

 

Thanks,

 

whiteatom

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  • 2 weeks later...
4 minutes ago, Titus said:

so I just precleared 8 new drives they all show 45gb data used but nothing is on them. Bug or the amount of writes it did to zero out the drive

That's normal for new xfs formatted drives, the larger the drive the more space is used for filesystem housekeeping/functions.

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  • 2 weeks later...

I have a question about preclearing external USB drives. I apologize if this has already been discussed. I have been shucking WD MyBook drives from the external enclosure, applying the tape to the 3rd pin so they work, inserting them into the array and running preclear 2x on the disk before use. So far I have had no issues. I'm wondering if I should be preclearing them as-is in the USB enclosure so that if I get a bad one, its much easier to repack and return, without any signs of cracking the enclosure open. I assume this will be slower over USB3 than connecting directly to SATA. During my last storage upgrade I ran 10 instances of preclear simultaneously on the array without issue. Will I hit any bottleneck trying to do the same using with the drives still in the USB enclosures?

Are there any other reasons I should avoid running preclear on untouched WD USB drives using USB?

 

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  • 2 weeks later...
I have a question about preclearing external USB drives. I apologize if this has already been discussed. I have been shucking WD MyBook drives from the external enclosure, applying the tape to the 3rd pin so they work, inserting them into the array and running preclear 2x on the disk before use. So far I have had no issues. I'm wondering if I should be preclearing them as-is in the USB enclosure so that if I get a bad one, its much easier to repack and return, without any signs of cracking the enclosure open. I assume this will be slower over USB3 than connecting directly to SATA. During my last storage upgrade I ran 10 instances of preclear simultaneously on the array without issue. Will I hit any bottleneck trying to do the same using with the drives still in the USB enclosures?

Are there any other reasons I should avoid running preclear on untouched WD USB drives using USB?

 

I see no reason why this would not work, but some users had problems with USB hard drives before. You can easily try it yourself, the odds are that it will work for you.

 

 

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I just got a couple of new drives and started to preclear them. Then i read in a thread from 2018 that its not longer necessary?

But in this thread it sems alot of people are still using it?

 

What has happened since 2018? Whats the current state of the preclear tool?

 

 

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24 minutes ago, Fifthy said:

I just got a couple of new drives and started to preclear them. Then i read in a thread from 2018 that its not longer necessary?

But in this thread it sems alot of people are still using it?

 

What has happened since 2018? Whats the current state of the preclear tool?

 

 

unRAID will do a clear of a disk that's added to the array if a) it doesn't have a valid preclear signature or b) the format of the drive isn't compatible with the array (usually XFS).

 

If you do use the preclear plugin or Docker, you do two things:

 

1) By running at least one full pass of preclear on a drive, you tend to discover if the drive has errors that may make it unsuitable for use within the array. This is useful for new drives that you want to validate - if you shuck USB drives like many of us, running the preclear while it's still in the OEM enclosure makes it easier to return/RMA the drive if it does have issues.

2) The other advantage is that a precleared drive is quicker to format and use once added to the array. If you just add the drive without a preclear, unRAID still has to zero the drive before letting you use it as part of the array and that takes time. Preclear just does this while the drive is not part of the array.

 

If you don't use preclear, chances are you'll be fine after unRAID finishes the zero process. Note that you can add drives that are formatted the same as your array (in most cases), but with one disadvantage. Say I have been using my drives on a Ubuntu/FreeBSD/*nix system and have them formatted as XFS (the current unRAID default). If I'm willing to let the system do a full parity rebuild, you can add drives that are already formatted and that contain data - you use the 'New Configuration' tool to force a full parity rebuild. This can save a lot of time in having to copy data into the array, with the caveat being that you'll have reduced speed access to the data while the parity is being built.

 

Personally, I prefer to preclear both old and new drives before adding them to the array. Certainly it's not strictly necessary but I'd rather put a drive in the array that I know has at least passed some basic testing before use. YMMV.

 

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1 hour ago, AgentXXL said:

unRAID will do a clear of a disk that's added to the array if a) it doesn't have a valid preclear signature or b) the format of the drive isn't compatible with the array (usually XFS).

 

If you do use the preclear plugin or Docker, you do two things:

 

1) By running at least one full pass of preclear on a drive, you tend to discover if the drive has errors that may make it unsuitable for use within the array. This is useful for new drives that you want to validate - if you shuck USB drives like many of us, running the preclear while it's still in the OEM enclosure makes it easier to return/RMA the drive if it does have issues.

2) The other advantage is that a precleared drive is quicker to format and use once added to the array. If you just add the drive without a preclear, unRAID still has to zero the drive before letting you use it as part of the array and that takes time. Preclear just does this while the drive is not part of the array.

 

If you don't use preclear, chances are you'll be fine after unRAID finishes the zero process. Note that you can add drives that are formatted the same as your array (in most cases), but with one disadvantage. Say I have been using my drives on a Ubuntu/FreeBSD/*nix system and have them formatted as XFS (the current unRAID default). If I'm willing to let the system do a full parity rebuild, you can add drives that are already formatted and that contain data - you use the 'New Configuration' tool to force a full parity rebuild. This can save a lot of time in having to copy data into the array, with the caveat being that you'll have reduced speed access to the data while the parity is being built.

 

Personally, I prefer to preclear both old and new drives before adding them to the array. Certainly it's not strictly necessary but I'd rather put a drive in the array that I know has at least passed some basic testing before use. YMMV.

 

 

Thanks for clearing things up, greatly appreciated.

 

I did a preclear because of your reasons 1 and 2, and although it takes ages to finnish i feel its worth it in the end.

 

I guess the fuss about preclear is because unraid already does a zeroing when adding drives to the array? 

Edited by Fifthy
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