Tool I use, VirtualBox, has a new version released 5.1. If you are new to this tool – Oracle has an announcement Oracle VM VirtualBox 5.1.0 is now available!, but for me it has two most important changes: Improved Performance and Improved Linux integration. I hope VirtualBox will be much faster now.
Release is out there in repository, just type sudo apt-get install virtualbox-5.1
and upgrade if you can. Because I can’t – another tool, Vagrant, that depends on VirtualBox, stops working. Issue Support Virtualbox 5.1 #7411 is already closed, but there is no stable version release with that patch. for now So I’ll wait until Vagrant 1.8.5 released.