At myhosting.com we have recently released a new service offering, Virtual Server Hosting which is a Virtual Dedicated Server (VDS) offering, a technology similar to Virtual Private Server (VPS). Wikipedia defines virtualization as an “abstraction of computer resources”. In more basic terms, computer virtualization allows for multiple independent instances of operating system(s) on a single physical box. Although virtualization is currently at the forefront of the x86 market, largely due to the efforts of VMWare, this is not a new technology by any means. In fact, virtualization has been heavily used in mainframe systems since the 1970s.
There are many vendors providing virtualization technology such as Microsoft, Xen, Parallels, VMWare, Sun Microsystems and Virtual Iron to name a few. Each technology is unique and has its own benefits and disadvantages. Although virtualization technologies are similar and the terms VPS and VDS are commonly interchanged, we need to distinguish between these two offerings as there are significant differences between them.
VPS technology was pioneered by Parallels Virtuozzo and utilizes one Operating system and carves it up to support multiple customers – this is referred to as OS Virtualization. This virtualization is referred to as container based virtualization. The major drawback of this technology is that all guests share one operating system. So if you want a Service pack or a hot-fix installed for your specific machine then you are at the mercy of all other guests who are sharing your Operating System. If you are unable to deploy a critical hot-fix because it breaks another customers/guests application, then you are vulnerable to an exploit and ultimately increasing your threat vectors.
VDS is offered by VMWare, Xen and by Microsoft with the Hyper-V offering. VDS technology enables you to carve up a physical machine into multiple virtual machines with independent operating systems – this is referred to as hardware virtualization. A Hyper-Visor sits between the physical components and the operating systems. With VDS the operating systems are independent and can be customized by each customer at will without affecting each other. With this consideration in mind, the advantage of VDS over VPS is obvious. By having your own OS you are able to manage and patch it at will. Patch management was an afterthought a few years ago, however with worms and bots targeting known vulnerabilities in Windows or Linux, patch management should be a serious consideration when choosing a virtualization solution.
Benefits of Virtualization with Microsoft Hyper-V
Modern computer systems are extremely powerful and systems with quad socket or quad cores are able to support many gigabytes of memory and storage. Running only one operating system and a single application on these types of systems would be inefficient. By utilizing virtualization technology we can consolidate multiple physical servers onto one physical machine. This enables the carving up of hardware resources so that they can be shared among multiple operating systems and applications without compromising security or stability.
In case you’re wondering about the availability of the system with all of this sharing, high end servers have multiple hot pluggable power supplies, hard drives and memory that can be swapped on the fly. So hardware failure can be mitigated or minimized.
One of the major advantages of virtualization is server consolidation. By virtualizing servers onto a single physical box, we are able to reduce the datacenter footprint. This helps reduce power consumption by two means; first, by limiting the number of physical servers, and second, by reducing the cooling required in the datacenter environment. Another side benefit of virtualization is that this consolidation reduces the number of physical machines that need to be managed by IT Operations staff.
Time to Market
By utilizing Hyper-V, we are able to use OS templates and deploy machines faster to market. There is no waiting for delivery of hardware. Using Microsoft Virtual Machine Manager, you can accelerate the provisioning of new machines and quickly meet changing and challenging business demands.
Disaster Recovery (DR) and Business Continuity Planning (BCP) are at the top of the minds of IT Executives. Natural or man made disaster can happen anytime and businesses need to be prepared for them. By utilizing Hyper-V virtualization, guest systems are stored as files on the Virtual Server file system. You can easily backup or move these files to another virtual machine and power up the Guest Operating System. There is no need for third party applications to help perform bare-metal disaster recovery. These files can easily be backed up and moved to a secondary site for business continuity planning.
The Snapshot feature provided in Hyper-V can be utilized to take a point-in-time snapshot of a machine. This allows you to revert to a previous state, for example, before an application or file was deleted. Snapshots should not be used as a backup solution but can be very useful in a testing/development environment, for example, if your Software Development team is testing a new application patch they can initiate a snapshot before the patch installation, and revert to this snapshot if needed. Snapshots allow for the ability to recover full guest systems, but not the ability to restore individual files which standard backups facilitate.
One of the major concerns with virtualization is high availability. If you have 15 guests on one physical server and there is a system failure, you have 16 servers down, not just one! This can be catastrophic. Earlier I mentioned simple hardware failures. Hard drives and power supplies can easily be swapped out when using hot pluggable servers. Microsoft kept this in mind when designing Hyper-V. They looked for a solution that can be used for both planned and unplanned downtime, this bore Quick Migration. Quick Migration provides high availability for Guest Operating Systems by leveraging Windows Server 2008 Failover clustering. Upon failure, virtual machines restart automatically on another node without the need for user intervention.
Where does it all net out?
My experience with Microsoft Hyper-V has been excellent. Having been involved with the Go Live program with Microsoft, I started working with Hyper-V while it was still in Beta. In my experience, the product has been both reliable and scalable, and has performed well with added benefit of leaving a smaller footprint in the datacenter. Having worked with other virtualization technologies, including Xen and VMWare, I can say that Hyper-V is just as proficient in terms of performance and scalability. Further, with integration into System Center Operations Manager from Microsoft and Virtual Machine Manager, I am able to manage my Hyper-V environment from a single interface and understand the health and availability of all Virtual Machines. What I also like is that the Virtual Machine Manager is versatile and not only supports management of Hyper-V, but also VMWare and Xen. And since Hyper-V is a Microsoft product, when running Microsoft guest operating systems it simplifies the support process. Going to one vendor for all our needs makes a great deal of sense when troubleshooting business critical issues.
The bottom line is that Virtualization helps reduce the Total Cost of Ownership (TCO). This is music to the ears of a CxO. Server consolidation, leveraging existing computing investments, minimizing datacenter footprint, and reduction of the cooling and power requirements are important benefit realizations for any IT department. The ROI of virtualization is swift, so you will see immediate savings. Additionally, with accelerated deployments, the ability to provision new servers at will on the Virtual infrastructure, there is no need to wait on new hardware and no need to compromise your speed to market. All in all, Hyper-V is a great product, and one that I would definitely recommend.
SoftCom Technology Consulting Inc.
- Hyper-V Explained: Microsoft’s Hypervisor Based Virtualization
- The Case for Hyper-V VDS over Dedicated Hosting
- Virtuozzo vs. Hyper-V: Comparing Container and Hypervisor Virtualization
- Virtuozzo OS Level Virtualization VPS Hosting vs. Other Hardware Level Virtualization
- Microsoft WebMatrix & Hyper-V VPS: The Perfect Pair