
Welcome to
Virtualization and Beyond
Scaling and Sizing your Virtual Environment
By Chris Paap, Technical Product Manager, SolarWinds
It doesn't matter if you're
an administrator over a modest virtual infrastructure of just a couple hosts
with a few virtual machines (VMs) or if you have the gargantuan task of
managing several hundred hosts with tens of thousands of virtual machines,
properly scaling and sizing is essential for continued operational performance.
However, the key to doing
this properly does not solely rely on predictive analysis and having concrete
numbers of what workloads will be added at a future point in time. In fact, as
most admins would attest, we usually lack the correct data to make accurate
growth predictions. So, aside from a magic crystal ball to make accurate predictions,
what are the key elements to consider when the time comes to scale and size
your virtual infrastructure?
Well, there is no one-size-fits-all
way to scale and size an environment to accommodate for growth and maintain
peak performance. Since every environment varies, the key is to identify your
goals related to what you're trying to accomplish.
For example, high
availability (HA) and fault tolerance are requirements of most production
environments, but what differs is the SLA time that is acceptable to recover
from an outage. How you provide HA and fault tolerance should be a factor in
determining how you scale.
In the past, most admins
would scale up with large hosts and pack these with as many VMs as possible so
they would have a few very large hosts with a high density of VMs. However, when
a high density server suddenly went down, all those VMs then had to start back
up on another host in the cluster. If you have this model, but also have an SLA
requirement with very little downtime during an outage (such as a hardware
failure on a host), you must ensure you have the underlying network, server and
software infrastructure to accommodate fast recovery.
For this reason, many admins
have started to scale out verses up to not only reduce
the risk of a single host going down and interrupting a high number of VMs, but
also because of the adoption of converged infrastructure.
The type of technology being
used in your virtual environment plays a role in scaling out as well. Converged
infrastructure combines network, server and storage into a single unit, and
hyper-convergence takes this a step further by taking a software-centric
infrastructure that integrates all these components into commodity hardware that
is grown in a scaled out fashion. Cloud also takes this a step further since
hardware is no longer the commodity, but instead CPU cycles, storage IO and
network IO are.
As obvious at it might seem, planning
is a key component to scaling, yet architectural decisions are constantly made
with a tactical milestone in mind as opposed to taking into account available
technologies and your goals.
An often overlooked component
of successfully scaling virtual infrastructure is monitoring. It's crucial you're
validating and confirming that your performance is meeting or exceeding your
expectations. And good monitoring should not just identify when performance is
bad, but identify trends and optimization actions to take to ensure continued
operational performance in order to get ahead of the curve. It's important to
note that your monitoring infrastructure will need to scale alongside the
virtual environment. Polling intervals, data retention times and the number of
virtual objects being monitored all play a role in the sizing, capacity and
performance requirements of your monitoring solution in order to keep up with
growth.
How do you scale and size your
virtual environment?
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About the Author
With 14 years of IT systems engineering experience across
multiple corporate environments, Chris Paap currently serves as a technical
product manager for hybrid IT
performance management software provider SolarWinds, where he
focuses specifically on the award-winning SolarWinds
Virtualization Manager. In this role, he is responsible for defining the product
roadmap and identifying key new features to solve IT problems.