0xfeedface Tech musings and rants

I've been tasked with designing and implementing a set of systems to serve as a NAS and a dedicated virus scanning machine. Three systems will be involved: a Windows Server 2003 box acting as a domain controller, a Windows Server 2008 box acting as a dedicated virus scanning machine for file uploads, and an OpenSolaris NAS. The OpenSolaris NAS will be authenticating via Active Directory and serving files over CIFS/SMB.

Because of how large this project is, I decided first to test configurations in a lab. When Windows Server acts as a domain controller, it likes to take full control over the network. It likes to serve DHCP, DNS, NTP, and act as the gateway. I needed to be able to have the virtual lab, then, on its own private network. I first tried VirtualBox, since it can natively do host-based networking. However, I learned that VirtualBox's support for host-based networking is practically broken in OpenSolaris hosts. Naturally, I turned to xVM.

Prior to choosing xVM, I knew OpenSolaris's cool networking feature Crossbow could do some pretty cool things. Crossbow can simulate a virtual layer three ethernet switch and I can set up virtual NICs (VNICs) and VLANs. Using crossbow and this tutorial, I was able to set up a private network to host my lab. I won't dive into the details in how to do it, since it's laid out really nicely in that tutorial (complete with pictures, yay!). One thing it didn't discuss, however, is that in order for your VNIC configuration to persist upon reboots, you cannot use NWAM. You have to disable NWAM via svcadm disable network/physical:nwam and set up oldschool static IP configuration via /etc/hostname.[vnic] and svcadm enable network/physical:default.

To sum up, OpenSolaris mixed with xVM and Crossbow provides an amazing virtual machine and lab solution. Crossbow is so simple to use and easy to integrate with other technologies, like xVM.

Overall, Sun xVM is easy to configure and run. Setting up a virtual machine on a headless VirtualBox installation takes a lot of thought. Setting up a VM with xVM takes a single command with virt-install. In OpenSolaris Build 133, you will be able to have the VM automatically start upon booting up the host OS. I'm very glad I switched from VirtualBox to xVM. xVM appears to be stable and fast.

I have only to gripes about xVM. First, my server has only 4GB RAM installed. xVM limits my host OS to 2GB memory. Since ZFS loves to use all available memory when it's not needed by other applications, I notice that ZFS performance has degraded slightly. Second, xVM uses VNC for remote controlling VMs. VNC is an antiquated, insecure, and inefficient protocol. I prefer the RDP VirtualBox offers over xVM's VNC.

From an administrative perspective, xVM beats VirtualBox hands-down. When combined with ZFS snapshots, xVM offers a complete solution I am looking for in a VM server. xVM has a lot of potential, especially when mixed with other OpenSolaris technologies like Crossbow.

In the end, xVM wins over VirtualBox for server environments.