I've been having issues trying to add a mirror to an NTFS volume in Win 8.1 64bit when using DISKPART and the Disk Management console. Both methods give me an error of "Virtual Disk Service error: All disks holding extents for a given volume must have the same sector size, and the sector size must be valid.", which I have have no problem accepting, EXCEPT that the drives appear to have identical and valid sector sizes. Below is some output that I believe adequately shows where my confusion is coming from:

C:\Windows\system32>wmic DISKDRIVE get name, bytespersector

BytesPerSector  Name
512             \\.\PHYSICALDRIVE1
512             \\.\PHYSICALDRIVE0

C:\Windows\system32>fsutil fsinfo sectorInfo C:
LogicalBytesPerSector :                                 512
PhysicalBytesPerSectorForAtomicity :              512
PhysicalBytesPerSectorForPerformance :         512
FileSystemEffectivePhysicalBytesPerSectorForAtomicity : 512
Device Alignment :                                      Unknown
Partition alignment on device :                         Unknown
Performs Normal Seeks

C:\Windows\system32>fsutil fsinfo sectorInfo E:
LogicalBytesPerSector :                                 512
PhysicalBytesPerSectorForAtomicity :              512
PhysicalBytesPerSectorForPerformance :         512
FileSystemEffectivePhysicalBytesPerSectorForAtomicity : 512
Device Alignment :                                      Unknown
Partition alignment on device :                         Unknown
Performs Normal Seeks
Trim Not Supported

C:\Windows\system32>fsutil fsinfo ntfsinfo C:
NTFS Volume Serial Number :       0x20181be7181bbaac
NTFS Version   :                  3.1
LFS Version    :                  2.0
Number Sectors :                  0x0000000036eb0fff
Total Clusters :                  0x0000000006dd61ff
Free Clusters  :                  0x00000000053f67fd
Total Reserved :                  0x0000000000000da0
Bytes Per Sector  :               512
Bytes Per Physical Sector :       512
Bytes Per Cluster :               4096
Bytes Per FileRecord Segment    : 1024
Clusters Per FileRecord Segment : 0
Mft Valid Data Length :           0x000000001d080000
Mft Start Lcn  :                  0x00000000000c0000
Mft2 Start Lcn :                  0x0000000000000002
Mft Zone Start :                  0x0000000000b38480
Mft Zone End   :                  0x0000000000b44ca0
Resource Manager Identifier :     F2A99BDB-DE42-11E2-AB89-9CBE7EB087BF

C:\Windows\system32>fsutil fsinfo ntfsinfo E:
NTFS Volume Serial Number :       0x6424a4dd24a4b408
NTFS Version   :                  3.1
LFS Version    :                  2.0
Number Sectors :                  0x0000000001387fff
Total Clusters :                  0x0000000000270fff
Free Clusters  :                  0x000000000026eaf7
Total Reserved :                  0x0000000000000000
Bytes Per Sector  :               512
Bytes Per Physical Sector :       512
Bytes Per Cluster :               4096
Bytes Per FileRecord Segment    : 1024
Clusters Per FileRecord Segment : 0
Mft Valid Data Length :           0x0000000000040000
Mft Start Lcn  :                  0x00000000000c0000
Mft2 Start Lcn :                  0x0000000000000002
Mft Zone Start :                  0x00000000000c0000
Mft Zone End   :                  0x00000000000cc820
Resource Manager Identifier :     26420F44-F037-11E3-BEC0-BC5FF4D5A85E

C:\Windows\system32>chkdsk

...
      4096 bytes in each allocation unit.

E:\>chkdsk
...

Any suggestions? I'd like for this to work if possible (adding a mirror), but part of the issue is also just sheer curiosity as to why this is occurring :). Thanks!

Hi,

Please try to back up your data in these disks, then format the two disk.

After that, follow these steps to create new mirrored volume:

1. Open the Disk Management.
2. Right-click on Unallocated space. Select New Mirrored Volume.
3. The New Mirrored Volume wizard appears. Click Next.
4. The Select Disks screen appears. Select the disks you want to add to the mirrored volume. Click Add.
5. Once the disks are added, you can specify how much disk space from the disks you want to be mirrored. This will be the same for all disks.
6. Click Next.
7. On the Assign Drive Letter or Path screen, choose the desired drive letter for the new volume. Click Next.
8. On the Format Partition screen, choose the option for Format this volume using the following settings.
9. Choose the NTFS file system. Enter a volume label. Select the option for Perform a Quick Format. Click Next.
10. On the Completing the new Mirrored Volume Wizard screen, click Finish. The new volume will be formatted and should show a status of Healthy on each of the disks to which the mirror was added.

Thanks for the reply, Karen.

I am not having issues with adding a mirrored volume - I can do that just fine. I have found that having an existing system volume on one disk, then adding an extra mirrored volume results in less than optimal performance.

Instead, I was hoping to use the 'Add Mirror' feature to create one large NTFS volume and mirror that on the other hard drive. My overall goal is to prevent downtime due to hard drive failure. However, this is when I start to get the above error.

Hi,

Sorry for my late response. Based on my further research, I have no other idea about this issue.

The only solution is use hard disks that have the same sector size to configure RAID volumes.

As my first reply, back up the data, format and re-mirror.

In addition, did you use virtual hard disk?

Based on the information I posted above, are the drives not the same sector size? If not, can you show the proper way to determine this information?

Firestorm 540, I was having the same issues that you were.  The only thing I didn't try was the exact suggestion that Karen Hu highlighted above.  It actually worked for me on my Windows 8.1 Pro 64-bit computer.  I initially had a partition from a 2TB drive that I wanted to mirror to a new 4TB drive.  Everything everyone else suggested failed. I even moved the data to another location and formatted the drive and that failed. I tried almost everything and all failed.  Karen Hu points out that you must go into Disk Management and highlight the unallocated section of a disk. Select it and right click on it.  Pick New Mirrored Volume. Follow the menus to Select Disks.  You already selected one disk so you must now move the available disk to the selected area.  Select Next after you pick your space size.  As the two drives were different in size, it picked the maximum that could be mirrored and unallocated the remainder.  It worked perfectly for me.  Thank you Karen Hu!

I have the same problem but "New Mirrored Volume" is greyed out.  I'm using Windows 8.1