Virtual vs. Physical Appliances: 4 Compelling Reasons for Change
by Ronan Kavanagh, CEO, SpamTitan
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Tags: anti-spam, email, security, spam, virtual appliances, VMware
October 10, 2008, 12:26 PM — SpamTitan —
Virtual v’s Physical Appliances – 4 compelling reasons for change
Executive Summary
Virtual Appliances have appeared on the horizon as an unstoppable force. Where traditional appliances supplanted the office and data centre server, the virtual appliance has taken this to a new level and in turn rendered the incumbent effectively obsolete. Where appliances addressed critical needs not addressed by office servers, they also introduced further complexities and difficulties which are easily resolved by virtual servers. This white paper takes a look at the advantages of virtual appliances in comparison with physical appliances and addresses some of the key benefits. Benefits which include ease of evaluation and testing, ease of deployment, streamlined redundancy and backup, and the key benefits of scalability and mobility....
The Need for Scaleable Architecture
Most organizations today spread their applications across servers based on functional
boundaries. Both large and small companies use email servers, file servers, web servers
and so on. Over time, the trend has been to dedicate a specific server for each function.
This allows for a scaleable, highly flexible architecture. As the organization grows, greater demands are placed on the infrastructure. Not just from an increase in the number of users, but also in terms of the geographic footprint. Branch offices will require their own servers for certain applications. Fault tolerance also plays a part, driving larger installations towards multiple, duplicated servers in preference over a single monolithic system.
As servers don’t generally require user interaction, the trend has been to use vendor supplied appliances for certain types of applications. An appliance allows for a relatively small footprint and also provides more of a plug and play infrastructure over the traditional server application experience. As load increases, new appliances can be brought on-stream and the load distributed evenly. The system administrator can maintain a surplus of similar appliances and install these in the event of failure or increased load. Dividing the application base into component parts and spreading these components across multiple appliances is a tried and tested method of delivering a scaleable architecture.
However, industry research by VMware shows that the system usage per appliance can be as low as 15% of the available processing power.† Effectively, the server budget is over six hundred percent higher than necessary. Maintaining a pool of idle servers on standby in case of increased load or for failure recovery, can adversely affect the efficiency even further. Amalgamating applications on each server can go a long way toward resolving the usage issues but at a cost. Running different applications on the same server loses the scalability of the appliance solution and can create security issues.
In addition, maintaining a homogenous environment of appliances is extremely difficult if not impossible. Complicating this is the need to upgrade different applications at different times. A new appliance can have a different platform configuration which will make it difficult to migrate users from an older appliance to a new one.
Virtual Appliances
A virtual appliance is one which subdivides the physical hardware into multiple virtual machines. Each virtual machine provides a ... See more at the source