Nowadays, any server operating system worth its salt packs virtualization hosting capabilities among its feature set. However, spinning up a guest instance and managing a virtual workload in production are two different matters.
Enter virtualization management vendor Convirture, and its Convirt 2.0 Enterprise product, which picks up where the out-of-the-box KVM and Xen-based virtualization capabilities of Linux-based operating systems such those from Red Hat, Novell and Canonical leave off, and serves a role similar to VMware's vCenter for these open source hypervisors.
For instance, the Red Hat Enterprise Linux 6 release that I recently reviewed includes a KVM hypervisor and all the facilities needed to connect to shared storage and participate in virtual network topologies. However, the easy-to-use graphical virtualziation tools that ship with RHEL don't extend beyond basic VM management.
Convirt 2.0 Enterprise provides administrators with a straightforward Web interface for carrying out the configuration operations required for deploying virtual instances in production. I used Convirt Enterprise to manage the RHEL 6 test host I built in my review of that product, paired this host with a second, Ubuntu 10.04-based virtualization host, and migrated virtual machines between the two systems. I didn't test Convirt with a Xen-based host.
While I'd have to spend more time using the product in our lab before making a full recommendation, Convirt Enterprise worked as advertised in my tests, and is well worth evaluating sites in search of management solutions for Linux-based virtualization hosts.
Convirt 2.0 is available in open source and enterprise editions. The open source edition is freely downloadable from Convirture's Web site. Pricing for the enterprise edition starts at $1,495 per host for up to 10 hosts, with volume discounts available. The enterprise edition adds high availability, backup and storage and networking automation functionality not offered in the open source edition.
I installed the Convirt server on an Ubuntu-based VM, and the process ran fairly smoothly. When I first fired up my server instance, I noted that its Web interface didn't take advantage of SSL encryption by default, but I found fairly straightforward instructions for configuring SSL among the product's documentation.
The product's Web interface roughly resembles the interface from VMware's virtual infrastructure client, with a similar hierarchy of data center, host groups, individual hosts, and the virtual machines served from each. For each level in this hierarchy, there were graphs that presented CPU and memory usage, and task lists that tracked operations such as VM power-on events, along with log messages for error and success.
Before adding my RHEL 6 host to Convirt's care, I ran a setup script on the RHEL system I was going to manage. The setup script allowed me to skip Convirt's network adapter bridging setup, as I'd already created a bridged interface on the host. As it turns out, I would have been better off had I started out with a fresh virtualization host install. When I placed a second, newly-installed virtualization host under Convirt's management, it took me some time to time to work through the differences between Convirt's bridging setup and the one I'd created.
Along similar lines, I found it trickier than I'd assumed to import my existing VMs from the RHEL host into Convirt. The product didn't recognize RHEL's VM format, although I found a conversion script on Convirture's forum that enabled me to bring my existing instance under management.
I added a second host to the Convirt server, an Ubuntu 10.04 KVM host, and set about configuring a shared storage device for migrating VMs between my hosts. I was able to add the storage at the server pool level, and the Convirt server applied the appropriate configurations to my separate hosts.
First, however, I had to resolve a snag with my Ubuntu host--I'd chosen a minimal set of packages for the host, one that left out NFS support. Since the Convirt management server wields root permissions over the hosts it manages, support for installing needed dependencies--or at least recognizing when they're missing--would be a nice feature to add to the product.
With both of my hosts up and running, I intended to move the VM I'd converted earlier from the local storage on my RHEL host to the shared storage I configured--as I'm accustomed to doing with vCenter--but I found no option for this through the product's Web interface. I took care of this migration by logging directly into my host and copying the image over. Once I'd done this, I could live migrate my VM back and forth between the hosts.
I also created a couple of VMs using Convirt's template capabilties. The product ships with a handful of basic templates, for CD-based installs of Windows and Linux clients, and for paravirtualized installs of Linux. I was able to modify these templates to specify virtual hardware characteristics, storage locations, networks, and to assign template disk images for my VMs.
I viewed the consoles of my virtual machines through a VNC connection piped through the Convirt management server. I used a standalone VNC client for this, but the product also offers the option of accessing VM consoles from a Java applet within the browser.