They&#x27;re definitely smaller.  Whether or not they&#x27;re safer depends on how you create the unikernel.<p>Many hypervisor security flaws which allow peeking between the VM isolation boundaries rely on sloppy protections around the virtualized virtual memory subsystem.<p>Most unikernel platforms don&#x27;t even expose a virtual memory semantic, and thus don&#x27;t consume these sometimes leaky hypervisor HAL implementation flaws.  They don&#x27;t use or expose the flimsiest floorboards in the hypervisor.  A full OS (including SmartOS) on the other hand... definitely does.