Kofax Communication Server 9.1 - Manual (Page 23)

Environment Guide Version 3.00.04
© Copyright Kofax, Inc. All information is subject to change without notice. 23
5. KCS in Virtual Environment
5.1 Overview on Virtualization
Nowadays in the IT business there is a strong trend called virtualization. It means that applications are
moved from a couple of physical, often underutilized servers towards virtual environments running on a
single or a few very powerful servers (hosts) that may host a couple of virtual machines, in the context of
which different (guest) operation systems (OS) may be running. Simply put, the virtualization creates the
illusion for the guest OS and applications that they are running on the dedicated physical machine.
The virtualization is often being implemented due to IT infrastructure consolidation and simplification (a few
fully utilized server resources, easily administrable instead of many physical servers, eventually running
different OS …).
There are several products in the market providing such a virtualization, e.g., VMware ESX Server,
XENSource, and Microsoft Hyper-V.
VMware ESX Server seems to be the market leader in the virtualization; therefore, there is also a strong
need to support Kofax Communication Server (platform) product line on this platform. This chapter focuses
on ESX server platform 3.x; however, certain sections are relevant for other virtual systems as well.
Note: VMware Workstation, VMware Player, and VMware Server (formerly called VMware GSX Server) are
NOT supported
Virtualization of IT infrastructure typically occurs in three steps:
1. Planning
During this phase performance data for current (physical) environment are being collected for a longer
period of time (e.g., 2 weeks) and suitable candidates for the virtualization are being chosen. This step
is necessary as no application vendor would be able to provide exact performance data/resource
utilization for the specific use case on the particular customer site.
While in the theory the most of applications can be virtualized, it makes obviously no sense to virtualize
applications with high resource utilization (80% and more) of CPU, memory, disk and/or network in the
physical environment. Furthermore, in order to reach high virtualization ratio (number of applications
virtualized on one ESX host) administrators would attempt to combine applications with different type
of workloads on the same ESX server: for example Microsoft Exchange that peaks between 9 and 10
am and 12-13 pm may be efficiently virtualized together with a web server peaking between 10 am and
12 am on the same ESX server etc.
Having collected the performance data administrator makes a plan which application to be virtualized
on which ESX host having in mind that the sum of their specific resource needs (e.g., disk) must not
exceed the capacity of the particular ESX server.