The release of Hyper-V in Windows Server 2008 this past summer illustrates the rapid adoption of virtualization: VMs have become so prevalent that Microsoft includes the technology as a standard tool in its server OS.
No one disputes that Hyper-V lacks the feature set available in VMware, including memory capacity, management of “sleeping” machines and support for other OSes. A chief differentiator between the two tools is VMotion, which can automatically move a load from one VM host to another without operator intervention. This capability will likely appear as Live Migration in the next release of Hyper-V.
Even so, there are compelling reasons to consider Hyper-V:
1. The Price
When it comes to cost savings, Hyper-V is attractive. The software is part of Windows Server 2008. (Microsoft has the second version, Release 2 — or R2, as it is known — available as a beta and plans to issue a final version later this year.) You also can download the beta at no cost, as well as a separate free version of Hyper-V.
In today’s economic climate, money matters more than ever to IT leaders. “CIOs are looking to save money, and virtualization is the no-brainer way to save money,” says Christopher Steffen, principal technical architect for Kroll Factual Data in Loveland, Colo. Steffen estimates a competing product would cost three times as much.
2. Power Demand
The second factor that makes Hyper-V attractive is power. Power is also a money issue, given that power and cooling costs have tripled in the past three years. And for some organizations, there is the issue of power availability, too. Depending on the location of a data center, access to the power grid can be an issue when it comes to expansion.
According to Microsoft’s research, an institution could achieve about a one-to-one energy savings for each server it consolidates, which means that as it adds virtual guests to the host, the power consumption does not increase radically.
3. Hardware Management
Beyond the obvious cost benefits of consolidation, a third reason to embrace server virtualization is hardware management. Running a data center with individual servers dedicated to single applications might seem simple, but it actually creates increased administrative overhead and can lead to footprint creep.
Additionally, virtualization can extend the life of older hardware because IT can move servers from production environments to support other needs, such as disaster recovery and program development, after consolidating on VMs.
Another driver is the ease of provisioning new guests. Setting up a new VM takes only a few minutes — so easy, in fact, that most IT shops now require a set provisioning process that includes appropriate approvals to avoid VM sprawl.
5. Learning Curve
That leads to the final reason to consider using Microsoft’s virtualization technology: familiarity. If the institution has servers already running Windows, then administrators will already have familiarity and competence using Microsoft’s system management tools.
No one disputes VMware’s superior feature set. Burton Group’s Wolf concludes that VMware’s product “is the most mature and will continue to win the feature war.” But for some users, Hyper-V offers a good-enough feature set with familiar management tools and a pleasing price tag.
Kernel for Kernel
Hyper-V uses a microkernel architecture, one of two types of hypervisors common in today’s virtualized environments. The other type is monolithic.
In both cases, the hypervisor sits between the hardware and its virtual guests.
In a microkernel hypervisor, the guest operating systems use native drivers to access processors, memory and input/output. The hypervisor handles the partitioning.
By contrast, monolithic hypervisors — in addition to partitioning the virtual machines on the host server — house their own hardware drivers that load to handle processor, memory and I/O services.