Identical Drives - Different Size?


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I just purchased (5) new WD 2-TB drives (WD20EARS-00MVWB0).  My parity drive is a Hitachi 2-TB drive.

 

I have begun replacing my existing (5) 640 Gig drives with the 2-TB WD drives - all the same model number (above).

 

However, two of the drives cause unRAID to report: "Stopped. Disk in parity slot is not biggest."  The drives look like they're reporting about 1,500 more bytes than the parity drive.

 

All of the drives went through a "preclear_disk" and all (5) have jumper 7-8 installed.

 

Does anyone know what is going on here, and how to resolve it?

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I just purchased (5) new WD 2-TB drives (WD20EARS-00MVWB0).  My parity drive is a Hitachi 2-TB drive.

 

I have begun replacing my existing (5) 640 Gig drives with the 2-TB WD drives - all the same model number (above).

 

However, two of the drives cause unRAID to report: "Stopped. Disk in parity slot is not biggest."  The drives look like they're reporting about 1,500 more bytes than the parity drive.

 

All of the drives went through a "preclear_disk" and all (5) have jumper 7-8 installed.

 

Does anyone know what is going on here, and how to resolve it?

Yes, we do...

 

Do yo by chance have a Gigabyte motherboard?  (or used the 2TB drive on a Gigabyte motherboard?)

 

Check out these entries in the wiki and learn about HPA (host-protected-area)

http://lime-technology.com/wiki/index.php?title=UnRAID_Topical_Index#HPA

and specifically:

http://lime-technology.com/forum/index.php?topic=4194

and here:

http://lime-technology.com/forum/index.php?topic=3894.msg34327#msg34327

 

Joe L.

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Now that you mention it Joe.....

 

I used another system to preclear the disks.  And it surely was a Gigabyte motherboard!

 

Can I just go back and "re-preclear" the two offending disks on a non-Gigabyte motherboard system?

 

This is a friends unRAID box with just too much data to back up.  I'm not a Linux guy and frankly a little worried at this point.  I really don't want to screw up.

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Now that you mention it Joe.....

 

I used another system to preclear the disks.  And it surely was a Gigabyte motherboard!

 

Can I just go back and "re-preclear" the two offending disks on a non-Gigabyte motherboard system?

 

This is a friends unRAID box with just too much data to back up.  I'm not a Linux guy and frankly a little worried at this point.  I really don't want to screw up.

No, you cannot "just" do that.

 

You must first reset the host-protected area.  Otherwise, the pre-clear will only see the artificially smaller size of the drive.

It will then set the partition size based on what it thinks is the "full" size available.

 

You should be able to use the hdparm -N command to see the native size and then again to reset the HPA to the full size of the drive.

Since you are planning to use the drive as the parity drive you really don't need a pre-clear signature on the drive, you just need to have it report its true size.

 

This post gives the basics: http://lime-technology.com/forum/index.php?topic=4194.msg37010#msg37010

 

Joe L.

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