[CentOS-virt] Can KVM be run "headless"?

Thu Nov 11 03:23:57 UTC 2010
Scott Dowdle <dowdle at montanalinux.org>


----- Original Message -----
> On 11/10/2010 06:46 PM, compdoc wrote:
> If I am running a windows client, I would run something like
> Ultra VNC server. And on my host, communicate with something
> like krdc. Am I correct?

There are a few ways to do it.

If I'm on a Linux box (which I am 99.9% of the time), I ssh -X into the host running the KVM virtual machines, and run "virt-viewer {vm-name}" and a graphical display of the machine pops up.  If I just want text access, I ssh into the VM directly.  If I want to run just one graphical app, I might ssh -X into the VM.

If you are on a Windows client then you can use an ssh client (PuTTY for example) or if you want the GUI stuff, you can install an Xserver app on Windows and tunnel the X traffic over ssh.  A nice free Xserver for Windows is Xming.

If you would prefer to run a remote display protocol server inside of the VM and connect with that you can install vnc-server or No Machine's NX server.  NX is a ton faster but the free version (not open source but free of charge) limits you to two user connections which is plenty for most people on a server.  Then you install the vnc-client or NX client on your Windows box and use that to connect to the remote display server in the VM.

> How do you start and stop your headless machines?

You can use virt-manager if you have GUI access to the host or you can use the command line tool virsh.  For example:

virsh list --all (Shows all VMs on the host and shows their status)
virsh start {vm-name} (Starts a VM)
virsh shutdown {vm-name} (Shuts down your VM)

You really should check out Red Hat's Virtualizaiton Guide.  They have a book quality guide that explains KVM, virt-manager and virsh.  


RHEL6 just came out today and they have greatly enhanced virt-manager and KVM... and you can expect a CentOS 6 release in 1 - 2 months... or so goes the pattern.  If you want to see what KVM is like in RHEL6 you can check out their updated Virtualization Guide:


Scott Dowdle
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