CentOS 7 supported as a host machine?

Submitted by cruiskeen on Thu, 05/28/2015 - 13:24

Hi - I cannot seem to find this - I just installed a new CentOS 7 system. I am trying to get it to behave as a KVM host machine. After some tussling with getting the bridging working right on the system (seems to be, anyway) I've tried installing some Centos 6 and 7 images over on it but am failing miserably. Cloudmin (and Cloudmin is running on a CentOS 6 machine) seems to construct the machine properly on the CentOS 7 host, but after it comes up networking doesn't work at all.

It's not completely clear now that I think about it that you are supporting CentOS 7 as a KVM host. Could you clarify (and if it is supported, give me a clue as to why the network interfaces will not work on the guest machine?)

Status: 
Closed (fixed)

Comments

Submitted by andreychek on Thu, 05/28/2015 - 13:32

Howdy -- yes, Cloudmin should run on a CentOS 7 host.

Which Cloudmin version are you using on your system there, is that Pro or GPL?

And just to clarify, the thing that isn't working is the networking? For example, your host can access the Internet just fine, but that doesn't work for any of the guests that are created?

Submitted by cruiskeen on Thu, 05/28/2015 - 13:56

It's Cloudmin Pro 8.0 -

but now that I've rebooted one of the virtual machines again I see that the REAL issue here with at least a Centos 7 guest is that though I've tried to configure 2 interfaces, only one works.

At least I'm now into the system. I'm trying to work out what happened.

I'll let you know if I need more help here. It doesn't really seem to like 2 bridges particularly.

Joe's picture
Submitted by Joe on Thu, 05/28/2015 - 14:02 Pro Licensee

I had a lot of trouble getting bridging working on CentOS 7, as well. And I still don't know exactly what I did to make it work right.

But, one of the things to check is to be sure routing is enabled. The install script I don't think turns it on by default (but should, and I have been meaning to fix that).

Submitted by cruiskeen on Fri, 05/29/2015 - 16:43

AAARRRGGGHHHH - this was all operator error on my part --- some place along the line I got the 2 bridges on the server confused and was putting the IP's on the wrong ones.

That's sorted -- I have another question that I'll post separately.;.

Submitted by cruiskeen on Sat, 05/30/2015 - 10:18

Spoke too soon apparently. I seem now to be able to create CentOS 6 KVM machines on this system, but any CentOS 7 machines (built from the CentOS 7 image from you folks) comes up just fine, but has no network available. This is getting really frustrating, and despite really wanting to start moving to CentOS 7, I am just having a lot of issues with this.

One thing I'd like to be clear on - in the CLoudmin method of running these KVM clients, is there ANY need to have any of the CentOS libvirt stuff installed or running? THe docs would imply that none of this should be installed.

Submitted by cruiskeen on Sat, 05/30/2015 - 11:33

Okay, I now have a little better handle on the parameters here. Gist of it is that I can start up either centos 6 or centos 7 machines successfully with networking as long as iptables is shut off. If iptables is running, then when the VM starts up, it never creates the .tap files in /kvm. Therefore, no network.

So -- my question here is what does iptables break, and how do I get it to come around?

Submitted by cruiskeen on Sat, 05/30/2015 - 12:16

Oh Geez Louise -- Okay - I see, it's a little confusion I caused when getting rid of firewalld and putting in iptables. Had a bad iptables rule in there that was breaking everything. You can close this, it's all working fine now after a whole lot of struggling with the bridging, etc.

Submitted by Issues on Sat, 06/13/2015 - 20:11

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