Modify Network Connections in KVM hosts running Windows

Submitted by rezitech on Sat, 02/04/2012 - 16:45

We just purchased Cloudmin, and have it deployed on a host in our datacenter. Our host machine is running Ubuntu 10.04LTS.

My host machine has several network connections: - "WAN" is connected to a public subnet and has full, non-NAT, connectivity to the Internet - "LAN" is connected to an internal network local to our datacenter machines only - "HOST" is a virtual network within our host machine with no outside connectivity

We already have a significant infrastructure deployed in the datacenter, and we make extensive use of our multi-network setup. We have a few Linux machines which connect to the "WAN" subnet and are public-facing machines. We have other (primarily) Windows Server 2008 virtual machines which connect to the "LAN" subnet. Lastly, we have a small number of virtual machines that connect to multiple subnets to facilitate routing of inbound email and some other services.

The problem I am up against with Cloudmin is that I don't seem to be able to connect virtual machines to one or more subnets on a per-virtual-machine basis.

A similar problem I am having, which is related and may be easier to answer, is that I can't figure out how to modify other settings for KVM on any given virtual machine. I need to be able to do things such as adding a PCI device from the host and allow it to be passed-through to a virtual machine, or modify the network, for instance.

Can you point me in the right direction?

Thanks so much!

Status: 
Closed (fixed)

Comments

Submitted by rezitech on Sat, 02/04/2012 - 16:48

Just to clarify a couple things:

The existing infrastructure in the datacenter is on other host machines without Cloudmin. I have Cloudmin installed on a new Ubuntu 10.04LTS-based host with KVM for virtualization.

I need to be able to deploy a new Linux and a new Windows virtual machine. The Linux machine needs to be on the "WAN" subnet, and the Windows machine needs to be on the "LAN" subnet. I also need another virtual machine to be connected to both "LAN" and "WAN" subnets.

Submitted by JamieCameron on Sat, 02/04/2012 - 18:26

Do your host systems have multiple ethernet interfaces? Typically this kind of setup is done by creating multiple bridge interfaces on the host (br0, br1, etc..) each connected to a different real ethernet interface (eth0, eth1, etc..).

Once this is done, you can tell Cloudmin to use all the host system bridges at Host Systems -> KVM Host Systems -> your host, using the "Bridges on host system for KVM interfaces" field. You should also select a different IP allocation range for each bridge, in the "IP address allocation ranges" field.

Finally, when creating a new VM you can select which host bridges it's virtual ethernet interfaces will be connected to. This makes is possible to create a WAN-only or LAN-only system, or one connected to both.

Submitted by rezitech on Sun, 02/05/2012 - 16:37

Thanks, Jamie.

I see what you're referring to, and that does help. I'm not seeing a way to modify those networking settings after the VM has been created. Is it possible to adjust the network connection associated to a non-Linux virtual machine?

Thanks!

Submitted by JamieCameron on Sun, 02/05/2012 - 18:56

For an existing VM, you can modify the bridge each network interface is connected to at System Configuration -> Network Interfaces. However, this only really works for Linux VMs ... which operating system are your VMs running there?

Submitted by rezitech on Thu, 02/09/2012 - 13:29

Jamie,

We can do that just fine for Linux VMs, as you say. The problem we are having is changing the bridge (or even adding or removing a bridge) for Windows VMs. We end up detaching the LVM volume, removing the VM config, recreating a VM, and then attaching the LVM volume. It's quite a bit of work.

I would really like an easy way to modify interfaces on Windows and non-Linux VMs. I don't need to adjust the IP addresses, but do need to attach or detach networks.

Travis

Submitted by JamieCameron on Thu, 02/09/2012 - 13:31

Currently there is no easy way to do this, but it is being worked on for inclusion in the next Cloudmin release. I will update this ticket when done..

Submitted by rezitech on Thu, 02/09/2012 - 14:23

Okay, great. Thank you.

Submitted by JamieCameron on Tue, 02/14/2012 - 00:43

Implementation of this feature has been completed, and it will be included in Cloudmin 6.1.

Submitted by Issues on Tue, 02/28/2012 - 00:46

Automatically closed -- issue fixed for 2 weeks with no activity.