oVirt or No Virt: Notebook Edition

oVirt is definitely not intended to be run on your notebook, and running something oriented toward powering whole data centers on a single, portable machine seems like overkill, anyway. For a Linux-powered notebook machine like mine, virt-manager is a great tool for spinning up all manner of VMs, and–while I’ve yet to get it running properly — GNOME Boxes offers another promising option for taking advantage of the KVM hypervisor that’s built into the Linux kernel.

However, since immersing myself in oVirt is part of my job now, and since I work with a lot of VMs on my work notebook, I wanted to see if I could come up with a notebook-friendly oVirt setup. The trouble with the single-machine rig that I described in my recent oVirt hotwo is that setting up the bridged networking that oVirt requires means disabling NetworkManager, the handy service that makes it easy to connect to VPNs and switch between WiFi connections. I wanted to avoid disabling NetworkManager.

I spent a bit of time fiddling with nested KVM — running an oVirt rig from within a VM on my machine. I was able to get this guest-within-a-guest setup working, but it was slow and unstable. Again, more sacrifice than I was willing to countenance for this.

In the end, I got my notebook-based, NetworkManager-friendly oVirt setup working by adapting the default guest networking configuration for virt-manager, in which libvirt provides a virtual network that acts like a NAT router for guest machines.

This was a little tricky, because when you configure a machine to be used as an oVirt virtualization host, libvirt gets commandeered by a higher-level component, vdsm (pdf), such that the default virtual bridge configuration is deactivated and you’re blocked from accessing libvirt directly.

In order to restore the virtual bridge setup, you have to provide libvirt with the user name vdsm@rhevh and the password you’ll find at /etc/pki/vdsm/keys/libvirt_password. I used the command line tool virsh to redefine the active “vdsm-ovirtmgmt” network to match my previous “default” network, and serve as a NAT router for the guest VMs on my notebook.

After making these changes, I rolled back the bridge-building changes to my ifcfg-em1 file, and deleted the ifcfg-ovirtmgmt file I’d created in step 12 of the howto. I also added the option “net.ipv4.ip_forward = 1” to /etc/sysctl.conf — without this tweak, my VMs were able to access the network as expected, but I wasn’t able to ssh into our otherwise reach my guests from my host machine.

I’ve had oVirt set up this way on my notebook for about a week now. So far, it’s been working really well. Before I shut off or suspend my notebook, I use the oVirt web admin in Firefox to put my host into maintenance mode. I also use the web admin to access the consoles of my guest machines through SPICE.

I’m using an Iomega ix2-200 desktop NAS box for NFS and iSCSI storage. Rich tools for setting up shared storage is one of the nice things about using oVirt instead of a desktop-oriented virtualization tool.

If the whole thing explodes, or just begins to droop into general suckage, I’ll update this post to reflect that. :)


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