removed
[ikiwiki.git] / docs / user / vKernelOverview.mdwn
CommitLineData
badcefcf 1## The DragonFly virtual kernels
2
3
4
7090708e 5***Obtained from [vkernel(7)](http://leaf.dragonflybsd.org/cgi/web-man?command=vkernel&section=7) written by Sascha Wildner, added by Matthias Schmidt***
badcefcf 6
7
d65ce9a9 8The idea behind the development of the vkernel architecture was to find an elegant solution to debugging of the kernel and its components. It eases debugging, as it allows for a virtual kernel being loaded in userland and hence debug it without affecting the real kernel itself. By being able to load it on a running system it also removes the need for reboots between kernel compiles.
badcefcf 9
10The vkernel architecture allows for running DragonFly kernels in userland.
11
12
13
14### Supported devices
15
16A number of virtual device drivers exist to supplement the virtual kernel.
17
18
19
20#### Disk device
21
7090708e 22The vkd driver allows for up to 16 [vn(4)](http://leaf.dragonflybsd.org/cgi/web-man?command=vn&section=4) based disk devices. The root device will be `vkd0`.
badcefcf 23
24#### CD-ROM device
25
26The vcd driver allows for up to 16 virtual CD-ROM devices. Basically this is a read only `vkd` device with a block size of 2048.
27
28#### Network interface
29
30The vke driver supports up to 16 virtual network interfaces which are
31
7090708e 32associated with [tap(4)](http://leaf.dragonflybsd.org/cgi/web-man?command=tap&section=4) devices on the host. For each `vke` device, the per-interface read only [sysctl(3)](http://leaf.dragonflybsd.org/cgi/web-man?command=sysctl&section=3) variable `hw.vkeX.tap_unit` holds the unit number of the associated [tap(4)](http://leaf.dragonflybsd.org/cgi/web-man?command=tap&section=4) device.
badcefcf 33
34