If you believe everything you read, you may think switching to Hyper-V is like switching coffee brands: "We're here at a data center, where we've secretly replaced your existing operating system with one that includes the free Hyper-V. Let's see if anyone can tell the difference!"
Inserting Hyper-V into a data center shouldn't involve an immediate cost increase. But once a Hyper-V implementation grows beyond a few virtual hosts, you ultimately need a better set of tools. This article explores Microsoft's solution for managing larger virtual environments, System Center Virtual Machine Manager (SCVMM), and the factors to consider when deciding whether to upgrade.
The pros and cons of free Hyper-V
Hyper-V's core virtualization enables you to host multiple virtual machines (VMs) on a single host. Simply install Hyper-V on a few physical servers, reboot and add VMs as needed. Hyper-V also provides a rudimentary mechanism for interacting with and administering these VMs. The native Hyper-V Manager console provides a location for managing virtual machines and their activities including powering on and off, cloning, taking snapshots, and even managing virtual networks.
But if you use Hyper-V Manager for more than a small number of virtual hosts, you'll see that its host-centric administration is limiting. You can refocus the console's attention toward different virtual hosts when you need to work with them, but there's no sense of "community" between the virtual hosts in your environment.
If you've incorporated high availability (HA) with Windows Failover Clustering, the problem becomes even more complex. This is because certain aspects of virtual management occur in Hyper-V's console, while other portions occur in the Failover Cluster Manager console. Remembering which console to use for certain actions, and ensuring that configurations are applied consistently, becomes challenging as your environment grows.
Considerations for implementing SCVMM
Even for the smallest environments, getting started with Hyper-V is affordable. As a result, these environments are likely to be the first to migrate to SCVMM. But small environments are small in part because of limited budget. Implementing Hyper-V because it's "free" is one thing. Paying an extra $869 per server for "enhanced management" is quite another.
With this added cost in mind, let's look at what you should consider before upgrading your Hyper-V environment to SCVMM. If one or more of these factors apply to your environment, the upgrade may be worth the cost.
- Multiple host management. SCVMM treats virtual hosts and their residing VMs more like a pool of resources than a set of physically separated equipment. With this aggregative approach, you gain comprehensive control of your virtual machines and, as the number of virtual hosts increases, a safer environment.
- Multiple hypervisor management. If you have virtual assets in your data center that are hosted on VMware's ESX platform, SCVMM's aggregation extends to them as well. It should be noted that SCVMM's integration with VMware occurs through the exposure enabled in VirtualCenter and not what is exposed by the ESX hosts themselves. With SCVMM, you can execute the management actions you would perform with VirtualCenter, but with a single view across Hyper-V and ESX hosts. For environments striving to reduce their software costs for low-priority VMs, one solution is to host tier-two VMs on top of Hyper-V, while retaining tier-one VMS on ESX.
- Template and library management. Managing the smaller aspects of a virtualization environment -- templates, ISOs, hardware profiles, etc. -- becomes an administrative hassle as the environment grows. To deal with this, Microsoft has included libraries in System Center Virtual Machine Manager. Libraries are a mechanism for placing database and file data in a single location for use within the virtualization environment. Keeping all of these "small bits" stored in your SCVMM library improves your administrative efficiency and keeps the environment secure.
- Integrated P2V. SCVMM includes built-in physical-to-virtual (P2V) and virtual-to-virtual (V2V) functionalities from VMware hosts. If you need these tools, SCVMM is a solid option for integrating them into your management interface.
- VM performance monitoring. For any virtualization administrator, the No. 1 priority is monitoring virtual machine performance. With multiple workloads on each host, the resource use of each must be carefully managed. On its own, Hyper-V provides this information through its PerfMon counters, but PerfMon is notoriously difficult to work with if your environment is larger than a handful of hosts and counters. Especially with its integration of Operations Manager, SCVMM provides better situational awareness of VM behaviors, which is critical to successful management of your virtual machines.
- Quick/Live Migration. One of the ways the cooperation between SCVMM and Operations Manager manifests is in the Performance and Resource Optimization (PRO) tips in SCVMM. These tips use monitoring data from Operations Manager to make educated decisions on tasks that need to be accomplished in the virtual environment. Environments that have more than a few hosts and need HA will find this capability critical for successful operation of VMs.
- Delegation of responsibility. It's possible to create a homegrown delegation of authority in Hyper-V by manipulating the Windows authorization manager. Unfortunately, the process is complex and requires special development. SCVMM includes several configurable levels of administrative delegation within its interface.
The $869 per virtual host price mentioned earlier is only one of the ways you can purchase SCVMM. The Microsoft SCVMM pricing website, lists three options. The price of $869 per host is for the server management license for each server. The cost includes the SCVMM server software that can scale to any number of hosts. SCVMM's Workgroup Edition, a cheaper solution for environments with less than five virtual hosts, is designed for small and midmarket environments and enables all the necessary server software and licenses for only $505.
A third option for enterprise customers that bundle their SCVMM purchase with other System Center products such as Operations Manager, Configuration Manager and Data Protection Manager. Because SCVMM integrates with Operations Manager for monitoring, this scale-up is a smart option if your organization plans a wholesale migration to Hyper-V for high-end production servers.
With each version update, Microsoft provides more features that make SCVMM a compelling addition for environments of any size. The as-yet-unreleased R2 version is no different. In part two of this series, you'll learn more about SCVMM 2008 R2's new capabilities and why, even for the most discerning environments, they make it production-ready .
|Greg Shields, MCSE, is an independent author and consultant based in Denver with many years of IT architecture and enterprise administration experience. He is an IT trainer and speaker on such IT topics as Microsoft administration, systems management and monitoring, and virtualization. His recent book Windows Server 2008: What's New/What's Changed is available from Sapien Press.|