[sheepdog-users] convert image with lost pieces

[Maxim Terletskiy]

Hi

While running "dog vdi check" I see this messages:
no node has 1c6c65000004f6

As I understand this means that my image lacks some data. I need to 
export this image to file, but qemu dying once reaching missing part. 
Tried "dog vdi read" with no success. In MooseFS if you lost some chunks 
you can zero it. How can I do something similar?