Critical Factors to consider when virtualizing Business Critical Applications: (Part 1 of 2)

Over the past few years, there has been significant acceleration in adoption of the VMware platform for virtualization of business critical applications. When vSphere 5 was introduced with its initial support for up to 32 vCPU many of the vertical scalability concerns that existed earlier were addressed. This has been increased to 64 processors with the later vSphere 5.x releases ensuring that more than 99% of all workloads will fit vertically.

Having personally worked in IT infrastructure for more than 20 years with a strong focus on implementing and managing business critical applications, I see a general reluctance from application owners to virtualize business critical applications. When virtualizing business applications there are many critical factors one should consider.  I seek to address the typical concerns of application owners about Virtualization with this multipart series on Virtualizing BCA.

CIOs and IT operations want to virtualize more because of the following advantages of virtualization:

  1. Infrastructure efficiency
  2. Simpler management
  3. Built-in availability
  4. Greater agility
  5. Simplified DR

But Application owners are usually reluctant because:

  1. Will my Application perform well? (Performance)
  2. Will it Scale? (Scalability)
  3. Can I meet my application SLAs? (Availability )
  4. Can I manage it effectively? (Manageability)
  5. Will my ISV support me? (Supportability)
  6. What’s in it for me? Will my application run better? (Agility & Time to Market)


Virtual performance is about 5-6% of physical for most business critical application workloads. The benefits of virtualization and productivity improvements overshadow the small overhead it introduces.

SAP Performance within 6% of Native:

SAP Performance on vSphere vs Physical

BCA1Exchange Server Performance:

Exchange Virtualization study discussed in Running Microsoft Apps on FlexPod for VMware  shows only a 5% performance difference between virtual and physical.

Exchange performance on vSphere


Database Performance:

SQL and Oracle performance close to Native as seen in the test results below.

SQL Throughput on vSphere vs Native
Oracle RAC performance vs Native on vSphere


It is proven that the performance of the common business critical applications are very close to their physical counterparts and performance should never be a concern for virtualizing them.  During virtualization there is usually a hardware refresh to the latest and greatest hardware with superior performance to existing systems. The small overhead of virtualization is easily offset while moving to this newer hardware as part of the virtualization migration.


With the vSphere 5.x platform, almost all workloads are amenable to virtualization.  VMware capabilities, such as vNUMA allows for NUMA aware operating systems and applications to run optimally even in virtual environments.

Scalability of vSphere

BCA5Workloads can scale up dynamically as demand increases with hot add capabilities for CPU, memory and storage resources as and when needed.  One can scale up or scale out based on the application requirements.

“Scale up” versus “Scale out”


These hot add capabilities are available only in virtualized environments and help right size environments and grow them dynamically, when needed without user downtime and loss of productivity. The following graphic shows the effect of increasing CPU on an Oracle DB server by 2 vCPU demonstrating the dynamic scale up capabilities of the vSphere platform.

Oracle Hot Add CPU Illustration


Part 2 of series can be found at  “Critical Factors to consider when virtualizing Business Critical Applications: (Part 2 of 2)”