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The secrets to managing disruptive migrations and consolidations

Enterprise IT is always on the move. Data centres, servers and storage are forever being consolidated, migrated or renewed, typically

involving virtualisation. Until now the only way to ensure business critical applications continue to perform during the disruption is to over provision capacity and over use IT staff resources. There is, however, a smarter, better and less expensive way. Here are four key steps. Chris James, Director of EMEA Marketing at Virtual Instruments.


irstly, you need to take a look at the current infrastructure. How are you measuring application performance across the data centre elements, especially the SAN where the critical applications and data reside? In most cases this is done element by element (switch, server, storage), rather than looking at an end-to-end view. The reason for this is often down to previous consolidations. Element tools can only give you a view of capacity, performance or utilisation on their part of the SAN. If you have multiple vendors supplying your SAN storage infrastructure, then you use each vendor’s tools to see their bit.

Have you ever had a major trouble ticket raised and the people responsible (both internal and external) for the elements blame one another? This finger pointing exercise is both massively inefficient and costly to the business. What you need is a view of the whole SAN and all its components regardless of vendor. Once you have that you can then go about baselining the application performance. The old adage of ‘you can’t manage what you can’t measure’ comes into play here. You need to know how an application is performing before a migration

28 I March 2012

or consolidation - if you don’t how it’s performing how will you know it is performing better in the new system?

Vendors are very reluctant to give a service level agreement for their new system but they will all assure you that: ‘Trust me the new system will be far higher performance with a far greater return on investment than before!’ Be sure you talk about performance rather than availability. Availability is, of course, massively important but an application can have five 9’s availability and still run slowly. It’s vital to know what you have currently and what to expect in the new or consolidated system.

Monitor the migration or consolidation in real-time Secondly, now that you know how the application is performing (i.e. you have set a threshold of 10 milliseconds per transaction as an end-to-end baseline), you can start the migration or consolidation process. Vendors are very helpful here and will provide services to

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