One of the things I have to do as a Virtual Infrastructure Administrator is evangelize value added with virtual machines. What are my stakeholders going to get out of this? Where’s the value added? Why should we use a virtual machines instead of physical machines? Here’s my explanation of some advantages and value added using VMware Virtual Infrastructure 3 from a system deployment standpoint.
This post will show a “before and after” view of system deployment. We had a pretty ‘vanilla’ setup of ESX on a few servers, but with a few simple changes to your environment with partition alignment, sysprep, and adding a patching policy can really add to the value your virtual infrastructure.
Here’s a quick comparison of physical system deployment and virtual machine deployment (with an ‘out of the box’ ESX setup):
Physical System
Virtual Machine
Discover system requirements
Discover system requirements
Contact vendor and receive system quote
Contact system stakeholders, provide a quote
Receive quote approval from system stakeholders
Receive quote approval from system stakeholders
Complete the procurement process
Template Deployment
System ships to our location
Document Virtual Machine
Unbox, Rack, Cable, and Document server
Configure OS*
OS installation and hardware configuration
Software Installation
Software Installation
\* Windows guests had to be configured, patched, and joined to the domain
Add in a few enhancements (mainly sysprep for Windows guests) and here’s the same comparison, only showing relevant costs while omitting costs which are the same among alternatives:
Physical System
Virtual Machine
Complete the procurement process
Template Deployment
System ships to our location
Unbox, Rack, and Cable server
Hardware configuration
Physical system deployment compared to Virtual Machine Deployment, omitting sunk costs
Changes we have made regarding template redesign have further shortened the time to deploy a new virtual machine, thus shortening the turnaround time for system requests.
Template Redesign
Our Windows and Linux virtual machine templates received necessary patches, updates as well as several enhancements to further realize ROI in with VI3.
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Higher I/O performance, reduced storage latency with partition alignment
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Eliminate configuration time necessity for Windows guests with sysprep
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Inclusion of a configured copy of VMware Tools in all templates
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Creation of policy mandating quarterly template updates
Partition Alignment
The majority of our existing Virtual Machines running the Windows OS were deployed from templates that were created with improper partition alignment. This improper alignment resulted in less than optimal virtual disk performance. Now, new Windows templates have been created with proper partition alignment which have higher I/O performance and reduced latency [ 1] [ 2].
Sysprep
VMware recommends using sysprep to decrease Windows guest deployment times[ 3]. Windows guests required several configuration steps when previously deployed without sysprep.
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Running NewSID to ensure no Active Directory collisions and renaming the computer
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Large OS and Anti Virus updating overhead due to lack of regular updates
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Joining the domain
All three of these previously mandatory steps have been completely replaced by sysprep answer files for Windows Server 2003 and Windows XP guests, significantly reducing the time spent in OS configuration. We have also followed most of the recommendations made by Leo Raikhman ( Linux, Windows) aside from the thin disk provisioning.
Template Patching Policy
The Virtual Machine templates had not been subject to a policy of upgrades due to scarcity of staff resources. We have identified system deployment time as a priority and taken necessary actions to ensure deployment time remains manageable and efficient. We now have policy in place to quarterly patch our template guest OSes.
[1] Storage Block Alignment with VMware Virtual Infrastructure, NetApp; page 7
http://media.netapp.com/documents/tr_3593.pdf
[2] Recommendations for Aligning VMFS Partitions, VMware; page 8-10
http://www.vmware.com/pdf/esx3_partition_align.pdf
[3] “Basic System Administration”, VMware; page 345
http://www.vmware.com/pdf/vi3_301_201_admin_guide.pdf