Everything was fine, but every time I start the Bitcoin Core, it take a hell load of time until it starts downloading the blocks, even after I've finished the initial bootstrap, as if you are forcing a car to move after letting a few guys give it a push.
This is on the VM and the main PC (host).
It's normal if you either :
1. Store the blockchain files on HDD
2. The HDD also used to store guest or/and host OS
3. Use shared folder feature, which is known to be slow. Source :
https://superuser.com/q/1025864