Some server virtualization technologies and strategies have straightforward best practices. Here’s how you install this, here’s the accepted hardware for that, etc.
But IT decision makers frequently face difficult choices when it comes to server virtualization technology. The platforms and hardware you select can have far-reaching consequences throughout your organization. And lots of factors go into selecting these virtualization options: features, ease of use, manageability and, of course, cost. Often, there is no easy choice among alternatives.
In the following face-offs, experts present contrasting views on some of the most important server virtualization technology options available to IT pros today. Consider the points raised in these debates to help you select the right virtualization options for your organization.
Blades vs. rack servers
There are lots of server virtualization technology options involving hardware. And hardware choices are among the most important decisions a virtualization administrator can make. A server’s size and available resources directly affect the performance and agility of virtual machines (VMs). But the type of server -- blades, rackmount servers, etc. -- also affects the cost and manageability of a virtualization project. In this face-off, two experts debate the merits of blades vs. rack servers for virtual environments.
Hyper-V Dynamic Memory vs. VMware memory overcommit
Thanks to server virtualization, administrators can use physical server memory more efficiently. Microsoft Hyper-V and VMware vSphere both have technologies designed for this purpose, but they take different approaches. Hyper-V uses Dynamic Memory, which automatically allocates memory to VMs based on need. And with VMware’s approach, admins can allocate more memory to VMs than the physical system has available. Experts Greg Shields and Eric Siebert weigh the pros and cons of Hyper-V dynamic memory allocation and VMware memory overcommit.
Related: How Hyper-V Dynamic Memory improves server consolidation
ISCSI vs. NFS
Server virtualization relies on shared storage, and administrators typically have two choices: block-based storage, such as Fibre Channel and iSCSI, or network file system (NFS) storage. Block-based storage is very reliable and offers high performance, but in most cases it carries a higher price tag. NFS, on the other hand, offers easy management and large data stores. Learn more about the pros and cons of each approach in this iSCSI vs. NFS faceoff.
Related: Storage options for virtualization
Server colocation vs. segmentation
One of server virtualization’s biggest benefits is the ability to run multiple workloads on one physical server. The question then becomes, “Which workloads should I run together on the same machine?” Some experts say it doesn’t really matter, because virtualization keeps individual VMs sufficiently compartmentalized. Others disagree and say improper colocation can waste resources and raise security concerns. Get the details on each argument in this face-off on server colocation vs. segmentation.
VMware vSwitch vs. Cisco Nexus 1000V
When it comes to virtual networking switches, VMware administrators have three main options: the VMware vSwitch, the VMware vNetwork Distributed Switch or Cisco Systems’ Nexus 1000V. In this VMware vSwitch vs. Cisco Nexus 1000V face-off, systems engineer Bob Plankers argues that the vSwitch is the best choice because it’s free, and users aren’t adding a second vendor they’ll have to deal with. But VMware evangelist David Davis counters that the Nexus 1000V makes network management easier, especially in existing Cisco shops.
Related: Why is the Nexus 1000V the only third-party distributed virtual switch?
VMware Workstation vs. Oracle VM VirtualBox
VMware Workstation and Oracle VM VirtualBox are hosted virtualization products that let users run VMs on various operating systems. Both come in handy for test and development environments and even offer more advanced use cases for server virtualization. Which one should you choose? The answer depends on your specific use cases and your budget, as detailed in this Workstation vs. VirtualBox face-off.
Related: Oracle VM VirtualBox 4: An overview
Xen vs. KVM
If you’re exploring open source virtualization options, you have two hypervisors to choose from: Xen and the Kernel-based Virtual Machine (KVM). Xen is the more established of the two, serving as the basis for several commercial hypervisors, including Citrix XenServer and Oracle VM. KVM, on the other hand, is relatively new to the market, but it is now the official virtualization technology of Red Hat Enterprise Linux. Learn about the pros and cons of each in this Xen vs. KVM face-off.
Related: Red Hat KVM deployments face uphill battle
This was first published in May 2011