The second day of virtualization coverage at Catalyst focused on virtualization as an enabler to workload mobility and orchestration, as well as standards-based management for the virtual data center.
For me, the highlight of the day was the DMTF unveiling the public release of the Open Virtualization Format (OVF) standard as a work in progress. In addition to the OVF announcement, DMTF president Winston Bumpus also announced the launch of the Virtualization Management subcommittee. Winston also announced that live demos of vendor OVF integration would be shown at Catalyst for the first time publicly. In terms of the best integration that you can use right now, Novell and VMware are at the top of the list. Novell is currently leveraging OVF in their ZENworks Orchestrator management suite, and VMware has supported using OVF to import VM appliances into Virtual Center since the end of last year. OVF is an XML-based virtualization metadata format and is fully extensible. All vendors that are contributing to OVF have very large long term plans for the spec. Look for OVF to start its transition from a standardized metadata format for importing VM appliances to the industry standard format for VM runtime metadata. There's no technical reason why this cannot happen, so to me runtime metadata seems like OVF's next step in its logical evolution. So it's foreseeable that proprietary VM metadata file formats such as .vmc (Microsoft) and .vmx (VMware) could be replaced with a .ovf file. The fact that OVF is extensible means that vendors can leverage OVF to define custom components of their virtualization stack. So even as virtualization architectures evolve, OVF has been designed to evolve with them.
Neither Citrix nor Microsoft had an OVF implementation at the show that is usable today. Instead, Citrix had developed a tool solely for the purpose of providing a demo, and expects its OVF implementation to be shipping early next year. While I would have liked to have seen more from Microsoft and Citrix, final work on the OVF standard is just wrapping up. So once the standard is ratified I expect all vendors to step up efforts to further support OVF. While there wasn't a shipping OVF solution for Citrix XenServer or Microsoft Hyper-V at the show, Citrix previewed an internal tool that facilitates Hyper-V to XenServer migrations, and vice-versa. With the tool, I could create a VM on Citrix XenServer, migrate it to Hyper-V and boot it up (the reverse process works too). All that's required is that you preload the paravirtualized device drivers for each hypervisor in the VM's guest OS once it's created. When the VM boots, Windows plug-and-play would load the appropriate drivers for the underlying hypervisor and the VM would be good-to-go. To Microsoft and Citrix's credit, they were the only vendors that were showing how to use OVF to facilitate hypervisor interoperability at the live demo. Still, with the spec nearly complete, it's time to see real implementations and not just a demo specifically prepared for Catalyst. Microsoft missed an opportunity to support OVF in System Center Virtual Machine Manager 2008 (it's still beta, but it's too far down the development path to add new features).
VMware CTO Steve Herrod offered an insightful glimpse of OVF's evolution and its future role in virtualization management. Key points highlighted in Herrod's session included:
- OVF's initial implementation is as a distribution format for virtual machines
- Packaging and deploying VMs via OVF includes several advantages:
- Verify licensing, security, integrity
- Resource requirements and placement
- Application Properties (IP addresses and passwords)
- Convert virtual disks to run-time format
- Provide runtime environment for application (customization and localization)
- Provide installation feedback to user
- Several VMs that are part of an OVF package can be instantiated as a single service object in the virtual infrastructure inventory
- OVF helps the industry deliver vendor-independent VMs that are easier to deliver and deploy
I presented a session on VM Mobility and Orchestration, with much of the focus on today's barriers to mobility. Those include:
- Live migration remains unavailable on several platforms (e.g., Hyper-V, Solaris Containers)
- Outside of VMware's DRS, dynamic VM load balancing technology is still maturing. Microsoft System Center Virtual Machine Manager Performance Resource Optimization (PRO) and Platform Computing's VM Orchestrator (VMO) are examples of further innovation in this space. Orchestration products from vendors such as Computer Associates and Novell are also providing innovative methods for automating VM relocation in response to changes in workload demands.
- Dynamic VM load balancing is going to transition from a reactive technology to a proactive technology, with vendors such as CiRBA providing intelligence to top level orchestrators to migrate VMs in anticipation of expected workload peaks based on historical workload performance patterns
- There's no technical reason why vendors cannot agree on a standardized virtual hard disk format. Such a format, in my opinion, would ease third party vendor integration and deployment of virtual appliances. Also, this standard format could include embedded checksums and tokening information that cause the disk to be authorized before it is mounted. This would provide a safeguard against theft of a virtual disk file.
- Differences in hardware-assisted virtualization remain a mobility barrier, forcing organizations to standardize physical clusters on AMD or Intel hardware.
- Several management issues, such as SLA assurance and compliance are difficult to effectively audit in virtualized environments.
- Improvements need to be made in physical server power management before running servers in a suspend state or at a reduced power mode will be an option. Ideally, organizations would like to run servers at a reduced power state as workload needs dictate in order to save on power and cooling costs.
That's it for Catalyst North America 2008's virtualization highlights. I hope to see some of you at Catalyst Europe in the October.
Posted by: Chris Wolf