Error “Unexpected VHD Feature Mask ‘6’” on Hyper-V backup or replication job

KB ID:
1742
Product:
Veeam Backup & Replication
Version:
6.x, 7
Published:
Last Modified:
2014-10-20

Challenge

The feature mask 6 error is Hyper-V specific. This KB covers that error and how to resolve it.

Cause

Feature mask 6 errors most often occur when a Hyper-V VM was a Physical to Virtual conversion using third party software. The issue is that some third party converter software creates the VHD/VHDX as a virtual hard disk with a Feature Mask of 6. This is not a feature mask recognized by Hyper-V and thus cause issues.

This is how the error presents itself:
 

User-added image


User-added image


User-added image

Solution

To resolve this issue, convert the disk from Fixed to Dynamic or vice-versa (then convert back to what you had been using).

If you are you using  server 2012 host environments ONLY, you will need to convert the disk to a VHDX format (from the older VHD).

Both of these methods essentially create brand new VHD files, and move the data from the old VHD to the newly created one. This sets the proper VHD information and should resolve any related errors.

Rate the quality of this KB article: 
3 out of 5 based on 16 ratings

Couldn't find what you were looking for?

Below you can submit an idea for a new knowledge base article.

Report a typo on this page:

Please select a spelling error or a typo on this page with your mouse and press CTRL + Enter to report this mistake to us. Thank you!

Spelling error in text:

Submit