periodic interrupted capturing on Virtual Box machine

[BSZAdmin]

Hi again,
i am trying to capture a win10 x64 image from a virtual machine (hosted by virtual box).
The image process starts normally but suddenly the current block section stops counting, the rate decreases an the remaining time increases.
A few minutes (sometimes hours) later the image process resumes for a short period an then the loop begins again --> current block section stops counting and so on

I am looking forward to your ideas.
Thx in advance
Greets