Virtualization Lifecycle Management
While, virtual machines and server consolidation provides impressive
and immediate ROI, it does not come without its
challenges. According to Gartner, virtual machine (VM) "sprawl" is
the number one concern when it comes to managing VM
environments. This article looks at VM sprawl concerns and
the role that effective Virtualization Lifecycle Management (VLM) plays
in preventing it from occurring in IT environments.
Most virtual servers begin by viewing a virtual machine as similar
to a physical one, but without the hardware cost. At the
beginning of a virtualized deployment, virtual servers view a virtual
machine the same as a physical one. It quickly becomes
clear that there are a number of significant differences between the
two, making it easier to experience sprawl in the virtual world than in
the physical one.
- Mobility - Physical
machines rarely move but virtual machines move a great deal. VMs
also tend to change state (e.g. powered on or off) more than their
physical counterparts – another aspect of mobility.
- Volume - A fully configured virtual server can be created in minutes, meaning many are easily generated.
- Identity - A physical
server has a specific identity tied to its physicality that is usually
attributed to the actual hardware. A VM on the other hand is a
great deal more ethereal.
- Lifecycle velocity - VMs
are created for many different reasons and life spans can be different
lengths. The speed at which a VM moves through all the stages of
its lifecycle can range from minutes to years, while physical servers
are more predictable.
These differences create problems for traditional datacenter
management tools that tend to be built for the “physical
world.” VMs are miscounted and this lack of visibility is
contributed to sprawl.
Sprawl is not defined by the number of virtual machines. The
definition of sprawl, “the proliferation of virtual machines
without adequate IT control,” has more to do with control than
numbers. If growth is not controlled then the organization is in
danger of sprawl.