Editing DragonFly BSD (section)

==== Virtual kernel ====
{{Main article|Virtual Kernel}}
Since release 1.8 DragonFly has a virtualization mechanism similar to [[User-mode Linux]],<ref name="towards-free-clustering" /> allowing a user to run another kernel in the userland. The virtual kernel (''vkernel'') is run in completely isolated environment with emulated network and storage interfaces, thus simplifying testing kernel subsystems and clustering features.<ref name="unix-for-clusters" /><ref name="kt-interview" />

The vkernel has two important differences from the real kernel: it lacks many routines for dealing with the low-level hardware management and it uses [[C standard library]] (libc) functions in place of in-kernel implementations wherever possible. As both real and virtual kernel are compiled from the same code base, this effectively means that platform-dependent routines and re-implementations of libc functions are clearly separated in a source tree.<ref name="peek-vkernel-1" />

The vkernel runs on top of hardware abstractions provided by the real kernel. These include the [[kqueue]]-based timer, the console (mapped to the [[virtual terminal]] where vkernel is executed), the disk image and virtual kernel Ethernet device (''VKE''), tunneling all packets to the host's [[TUN/TAP|tap]] interface.<ref name="peek-vkernel-2" />