Virtualisation is one of those technologies that will always shine on a CV, as it’s increasingly relevant. Our panel of expert advises on common questions relating to skills.
Q: Remind me, what is virtualisation?
A: Virtualisation has been the method of choice for server consolidation over the past five years or so. A set of physical servers can be virtualised into a series of ‘virtual images’ - or data only. Several of these can then be hosted simultaneously on a single physical server using a hypervisor layer, such as VMware’s ESX Server, which allows more efficient use of hardware resources including processor and memory. These virtual images are also portable, easy to migrate from one physical platform to the next.
David McLeman, managing director of Ancoris
Q: What IT skills can be transferred to virtualisation?
A: Any competent systems administrator should be able to set up virtualisation. Most of the skills involved are the same as those needed for a full server, such as installing the operating system, and getting networking going. The virtualisation technology is not that different from a lot of things that systems administrators manage on a daily basis.
Nick Craig-Wood, co-founder of Memset
Q: What skills are needed when working with virtual severs?
A: If you don’t understand storage technologies such as fibre channel, capacity and backup systems when working with server virtualisation, you’ll likely run into trouble. Likewise you’ll need decent networking skills. At the very least be sure that you understand the fundamentals of your chosen protocol, such as fibre channel over Ethernet (FCOE). Performance troubleshooting skills are of the utmost importance when working with server virtualisation as bottlenecks can quickly build up.
Robert Rutherford, CEO of QuoStar Solutions
Q: What security pitfalls do I need to beware?
A: If you plan to add virtual machines to physical servers you need to carefully consider how that affects network security. The key message is to look before you leap. Virtual local area networks are used to segregate traffic on traditional networks, but when it comes to virtual networks, people often forget to apply the same methodology. A virtual switch is required to control how applications and files interact with one another to ensure the network is correctly segmented and access to data is restricted as appropriate.
Lewis Honour, Security Practice Director at Intergence Systems
Q: How do I optimise application performance?
A: To maintain excellent application performance in a virtualised environment, it is crucial to have the right management tools in place. By monitoring the real-response time of applications, performance can be benchmarked against service level agreements and problems can be addressed as soon as they arise. The IT department also needs to manage how individual requests are optimised, routed and transformed. Intelligent traffic management policies can evolve over time as user demands and needs of the business change. Directing traffic to data centres in either San Jose or Amsterdam, depending on the location of the request, can reduce application delivery time by two seconds.
Owen Garrett, cloud computing and virtualisation specialist, Zeus Technology
Q: How is network capacity affected by virtualisation?
A: Once companies ‘go virtual’ the number of virtual servers tends to increase beyond expectations because they’re easy to deploy and businesses wish to keep applications separate. If the network has not been sized correctly or insufficient bandwidth has been commissioned to supply the physical servers, congestion can ensue and cause delay. It's an issue that's glossed over by vendors when they push the move to virtual networks.
Lewis Honour, security practice director at Intergence Systems
Q: How do I cost virtualisation?
A: Virtual resources can be harder to price. This is because the IT department has to calculate how to apportion chargeback to the departments who are using that server as a part of a shared resource. The fact that user requirements change over a fixed accounting period also complicates things. The spiralling cost of power is an incentive for IT and facility management departments to get together to understand unit costs of office space, server rooms, equipment and utilities. A rising tide of savvy cloud-based IT providers, including Amazon, EC2 and Salesforce, that charges on usage, will only add to the momentum for IT staff to understand costs.
Robin Webster, infrastructure consultant, Centiq
Read Part I of the Virtualisation Clinic.
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