Unassigned Devices Preclear - a utility to preclear disks before adding them to the array


dlandon

Recommended Posts

5 hours ago, propman07 said:

Does that imply that a device attached via unassigned devices as an example is not reliable to read/write data from/to?

Not at all.  It's that USB can be flaky, random disconnects and reconnects, not passing drive information completely or accurately, other issues.

 

Unassigned devices is just a convenient way to manage disks not assigned to the array or pools. It doesn't have anything to do with the attachment method of said drives, be it SATA, eSATA, SAS, or USB.

 

Some USB chipsets can work ok, but it's hard to know ahead of time whether a specific combo is going to give issues.

 

Link to comment

I have a drive that is all zeroes but does not have the signature. Can I use this plugin to read the drive, verify that it is all zeroes, and then write the signature? I don't see that in the options. All the options either write zeroes or read the signature. I have zeroes but I don't have the signature. I could of course just write all new zeroes but I imagine reading is less wear.

Thanks!

Link to comment
29 minutes ago, mackid1993 said:

I have a preclear going on 3 drives, they are nearly done but one is about 2 hours being the others. If I stop my array to add the two completed drives will that break the preclear that has yet to finish?

If you stop the array, UD will pause preclear on the drives being precleared and they can be continued once the array is restarted.  Click on the play arrow on the UD Preclear GUI page and the paused preclears will restart.

Link to comment
1 minute ago, dlandon said:

If you stop the array, UD will pause preclear on the drives being precleared and they can be continued once the array is restarted.  Click on the play arrow on the UD Preclear GUI page and the paused preclears will restart.

Thanks so much!

I'm replacing all of my very old 3 and 4 TB drives with new higher density 12 TB drives so I have to break parity to do the transfer. My goal was to add the two precleared drives and start moving data and when the third one finishes it'll be my parity disk.

I have redundant backups of everything so I'm not worried about data loss.

Link to comment
Just now, mackid1993 said:

Thanks so much!

I'm replacing all of my very old 3 and 4 TB drives with new higher density 12 TB drives so I have to break parity to do the transfer. My goal was to add the two precleared drives and start moving data and when the third one finishes it'll be my parity disk.

I have redundant backups of everything so I'm not worried about data loss.

If you reboot the server, that paused status gets lost, but you can still resume a preclear from where it left off on a particular disk.

Link to comment
12 minutes ago, dlandon said:

If you reboot the server, that paused status gets lost, but you can still resume a preclear from where it left off on a particular disk.

Thanks! The goal is not to reboot until the old drives have been dod wiped and are ready to be pulled.

Link to comment
On 3/22/2024 at 4:49 AM, NominallySavvyTechPerson said:

I have a drive that is all zeroes but does not have the signature. Can I use this plugin to read the drive, verify that it is all zeroes, and then write the signature? I don't see that in the options. All the options either write zeroes or read the signature. I have zeroes but I don't have the signature. I could of course just write all new zeroes but I imagine reading is less wear.

Thanks!

I'm in the same boat. Just precleared two drives and they wrote the signature but are failing the signature verification. What did you end up doing? Did you just rerun preclear? Or RMA the drives?

Link to comment

I know that a clear for unraid writes all zeros to a drive. I have heard that it's possible to recover data from a drive that has been cleared in this manner because the overwrite was done in a known pattern (all zeros). I'm not sure if this is true or not but just in case it is, is it possible to use this plugin to overwrite a drive with random zeros and ones?

Link to comment
32 minutes ago, wgstarks said:

is it possible to use this plugin to overwrite a drive with random zeros and ones?

  

On 2/27/2022 at 9:55 AM, dlandon said:

Erase and Clear Disk - random patterns are written to the disk and then zeroes are written.  This is a good choice for a disk to be discard to ensure all traces of files are removed.

 

Link to comment

Is there a way to just verify the signature?  I'm pretty sure I precleared the drive earlier, but would like to verify the signature.

 

I see it in unassigned devices, but in the GUI all I get is the start preclear option.  Don't want to hit it as I'm afraid I'll have to start the 3 day preclear process over and not need to.

 

thanks

Link to comment
29 minutes ago, lovingHDTV said:

Is there a way to just verify the signature?  I'm pretty sure I precleared the drive earlier, but would like to verify the signature.

 

I see it in unassigned devices, but in the GUI all I get is the start preclear option.  Don't want to hit it as I'm afraid I'll have to start the 3 day preclear process over and not need to.

 

thanks

When you start the preclear you’ll get a popup that lets you set what process you want to run. Verify signature is one of them.

https://forums.unraid.net/topic/120567-unassigned-devices-preclear-a-utility-to-preclear-disks-before-adding-them-to-the-array/

  • Like 1
Link to comment

I'm attempting to do a preclear on a new 8TB drive. I plugged the drive into a hot swap bay, and it shows up in Unassigned Devices and the Preclear Disk plugin. I start the preclear using the default options and hit Start. The drive list in Preclear says "Starting... X", and there is only one line in the Preclear logs executing the script with the selected options. I have not stopped my array to assign the drive yet.

 

My question is, how soon should I start seeing logs that something is happening or some kind of indicator that the script has actually started?

Link to comment

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.