On 12/09/17 21:33, Marcin Dulak wrote: > I'm not opposing changes to the controllers, only the random behavior of > the centos/7 image depending on the version of virtualbox: > https://www.virtualbox.org/ticket/16387 Nice to hear that. The IDE images default to using the host caching system, which wastes host memory to cache things cached by the guest anyway (that decreases the host performance, especially if youțre not using it exclusively for running VMs). Things like NCQ offered by SATA but not IDE increase the performance even more. FWIW, I've seen the "IDE" vs "IDE Controller" issue even with the same release of VirtualBox, by instantiating a box several times. I assume it's a bug in VirtualBox that our particular config file happens to trigger. Perhaps we could rebase the config file in ImageFactory on what VirtualBox generates, but that would be Ian's decision. Regards, Laurențiu