I have always preferred a holistic approach to designing a virtual environment, but meeting all of the business needs often means dealing with multiple vendors. Value-added resellers (VARs) have a great opportunity to make technologies work together and become a customer's one-stop shop for virtualization consultation and infrastructure design.
Certifying virtualization technology compatibility
So, a customer decides he wants a virtualized infrastructure. What considerations should you research? First, you must choose the server virtualization technology, keeping in mind what storage hardware the virtualization vendor has certified. Review VMware's storage compatibility list and XenSource's hardware compatibility list (HCL). As of this writing XenSource had only one storage system listed -- the HP EVA 4000 storage area network (SAN) -- and it was submitted by the community, not certified by XenSource. I could not find any sort of HCL for Microsoft Virtual Server.
If a customer wants to use hardware that is not on a vendor's HCL, the hardware may still work; but that particular vendor may not support the hardware and software combination being used. This is where you can offer your own hardware certification process and support. It is a riskier move, but it could differentiate you from the competition.
Benefits of VMware technologies
If it sounds like I am leaning toward VMware as the best choice for server virtualization, I am. It is the most mature of all the server virtualization technologies, and the company keeps the innovations coming with every release. If you are going to provide a customer with a holistic approach to a virtualized environment, it would be best to use the most widely supported platform. The fact that there is only a single community-submitted storage array on the XenSource's HCL should reveal that XenSource has a long way to go before it is accepted as a mainstream virtualization product. VMware's documentation, support and community is also very rich. Also, VMware is the only vendor so far to offer bare-metal virtualization, which allows virtual machines to run at closer to native speeds without the overhead of a host operating system. Let's also not forget the biggest reason to use a SAN with VMware in the first place: VMotion. If the customer is at all concerned about downtime, VMware's Virtual Infrastructure 3 with VMotion and high availability are the only way to go. Currently, VMware is the only vendor of the vendors listed in this article to support a "live migration," and it has been for a while.
I do not mention Microsoft Virtual Server because, in my opinion, it is not a true enterprise option yet. Alternative technologies like XenSource do have their merits for some companies. XenSource has a lower cost, though it is my opinion that you get what you pay for: XenSource is not as mature as VMware and lacks features like VMotion, high availability and distributed load balancing. Also, some customers may want to go with an open source solution for philosophical reasons. Ultimately, this decision will depend on how much influence the information technology department has when deciding on which business systems infrastructure components to support.
Choosing which virtualization services to provide
As a VAR trying to package solutions for customers should you focus on the underdog niche market (XenSource), learn both (VMware and XenSource), or focus on the majority technology (VMware)? I would choose either XenSource or VMware, but not both. If you choose both, you may lose your focus and become mediocre in one or both technologies. If you choose XenSource, you will probably have fewer customers, but you may be able to charge a premium for services. If you choose VMware (the safe bet) the number of customers available to you will be much greater. It is also easier to build a holistic virtualization approach based on VMware because of greater hardware compatibility, support, documentation and community.
Once you have worked with your customer to decide which virtualization technology to use, you can work out the foundation of the virtualized environment. If the customer is a small or medium-sized business (SMB), chances are you will be looking at iSCSI storage instead of Fibre Channel. If the customer currently has no SAN, I would look at iSCSI first unless there is a compelling reason to go with Fibre Channel. The flexibility, cost-effectiveness and ease of setup offered by iSCSI makes it a compelling choice. A good storage foundation with redundancy built in will go a long way when it comes to implementing a stable virtualized environment.
After the storage and server virtualization technologies are chosen, you can turn your attention to other pain points. This may include managing the new virtual environment or application management. You may sell application virtualization technology, such as Altiris SVS, Thinstall or Softricity to complement the newly virtualized environment. You may also want to provide P2V (physical to virtual) migration services using software such as PlateSpin's PowerConvert, or extra management and utilities such as those offered by Veeam. Whatever ancillary services you offer, make sure to guide the customer through the choices they have and the benefits of each.
When your plan is all laid out for the customer, you can offer implementation services. It may be some customers first exposure to virtualization technology of any kind. If they are implementing a complete virtualized infrastructure, it will be important that they have a partner who can guide them through the complexities of a virtualized environment and provide support. A VAR can offer local services above and beyond what individual product vendors can offer. Remember to keep in mind that the virtualization technology is just one piece of this type of infrastructure. To create a solid virtualized environment, you need a new way of thinking about the traditional IT infrastructure. This is where a VAR offering packaged, holistic solutions can truly shine.
About the author: Harley Stagner has a wide range of knowledge in many areas of the IT field, including network design and administration, scripting and troubleshooting. Of particular interest to Harley is virtualization technology. He was the technical editor for Chris Wolf and Erick M. Halter's book Virtualization: From Desktop to the Enterprise and currently writes his own blog at www.harleystagner.com. Harley is also SearchSystemsChannel.com's featured virtualization expert. Ask Harley a question today.