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Windows 10 drive order vs. BIOS drive order


Kashim

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Hi. I recently built a file server using an Asus ROG Crosshair VIII Hero motherboard. The seven drives that were installed show up in the correct order on the BIOS screen. But in Windows Disk Management the order is changed from 1-7 to 7, 6, 5, 1, 2, 3, 4. Is there a way to make the drive order shown in the BIOS match the drive order in Windows 10?

Is my only option to physically swap the drives around until I get the order I want in Disk Management? (Meaning the BIOS order will be scrambled.) And if I do that, would it cause an issues in Windows? I assume drive letters won't change and Windows would simply re-detect the moved drives on their new SATA channels. But would it leave behind any junk in the registry referencing back to their original SATA positions that could cause any future problems? Any suggestions would be appreciated.

Edited by Kashim
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Yep, the issue is known for previous versions of Windows, evidently the (stupid) Windows 10 has not been fixed, see:

https://support.microsoft.com/en-sg/help/937251/disk-drive-numbers-may-not-correspond-to-the-sata-channel-numbers-when

in practice it depends on how fast the device is in communicating with the plug 'n play subsytem, so that you may (or may be not) able to change order switching (SATA) ports.

Drive letters are assigned to drives (that do not mean disk drives, but rather partitions or more exactly volumes).

On BIOS, disks are normally partitioned MBR style, so you can have both primary partitions that are also volumes or extended partitions that can contain one or more volumes.

On UEFI, disks are normally partitioned GPT style, so you have only primary partitions that are also volumes.

Drive letters are assigned in Windows automatically (unless intentionally/manually assigned)  to volumes along a set of "rules" that depend (in part) on the order of the disks (the actual diks drives and that get rather complicated where extended partitions and logical volumes are involved), but once they are assigned they are "static" unless something changes, the drive letter is assigned to the volume (even more properly to a disk extent) based on the Disk Signature and the offset (and size) of the volume, the info is stored in the Registry and is independent from the disk order in DIsk Manager or Diskpart.

So the issue usually comes not with drive letters assigned to volumes on the internal disks, that are pretty much "static" (physically), but if you have disks that you plan to hot-swap (or hot disconnect/re-connect) there could be issues, though It is difficult to say what can happens if, 

If you use USB devices and/or network mappings, this may be of use:

https://www.uwe-sieber.de/usbdlm_e.html

jaclaz

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It is possible that you may never be able to get the disks to enumerate in the order you want in Windows. You could always try it, since unless you are using a RAID controller or these devices are in any vdisks, it shouldn't make any difference to Windows.

BUT: what you can do instead is use the volume label to identify what port is being used. And also you could write on the disk itself which port it is connected to.

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Thanks for the replies. I will probably end up physically swapping the drives around until the order is correct in Windows. All drives are connected to internal SATA connectors and there's no RAID control, so it should be fairly painless. The BIOS order of the drives does not matter to me at all and it was a mistake on my part to assume that the BIOS order would match the order in Windows.

 

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