VHDs do not get mounted - The parameter is incorrect



Product: ProfileUnity

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Expires on: 365 days from publish date

Updated: December 19, 2017


VHDs do not get mounted - The parameter is incorrect



There are 2 errors showing on the screen at logon.

1.Windows error

The parameter is incorrect

2. Portability error

Virtual Disk could not be created..  Exit code was: 87.  Message was: The parameter is incorrect.


It is a problem with Windows 7 VHD’s which do not support a block size of 4096. The issue was found on a file server 2016 Datacenter, configured as a Failover Cluster running Storage Spaces Direct which requires minimum block size of 4096. There is no problem mounting VHDs on Windows 10. 

The following URL shows a Microsoft reference to this problem.



To check the block size on a servers disk determine the disk number in disk management ( in this case it will be Disk 2)




Open the run command prompt and type msinfo32



Expand components Storage and click on Disks



Note the Bytes/Sector size, in this case it is 4096, and that is not a compatible block size for windows 7



Below is a screenshot of the disks on the working cluster, the block size is 512. This clustered file server is configured to use a shared raw disk presented from VMware and is not using the Storage Spaces Direct feature of 2016 for its clustering




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