Implementing a virtual infrastructure is extremely compelling from a cost perspective and management. There are four main challenges outlined in a recent survey “Strategies to Improve IT Efficiencies in 2010” by Forrester.
1. Assessing Server Sizes for Virtual Servers
2. Assessing Performance and workload needed
3. Major performance issues during peak loads
4. Managing the complexity of a virtual infrastructure
These issues are all tied in to the need for implementing a well planned virtual infrastructure. The complexity is greater than in a traditional environment so having the best technical experts do a comprehensive capacity plan and then design is paramount for success. The plan needs to go beyond standing up the infrastructure and include how the virtual infrastructure will be maintained.
Once you have the virtual infrastructure in place you will need to address:
1. Visibility – Where is the application and where is the problem?
2. How do you prove source of problem to the component owner?
3. Where will the next constraint or problem arise?
4. Planning for the next expansion
5. Dealing with applications resource contention
6. Over use of VMotion – simultaneous moves in same LUN can cause poor performance
Virtualization creates the most dynamic data center that IT management has seen – The mantra becomes “constant monitoring, modeling and planning.” Depending on the size and complexity of your virtualized infrastructure the technical management team should at least once a quarter and maybe as often as weekly do a capacity planning style exercise based on current utilization and planned expansion.
Here are the virtualization mistakes to avoid:
1. Racing to deploy and failing to plan completely
2. Configuration mistakes – check before using default settings
3. Not enough storage IOPs
4. Resource contention – not all applications work well together
5. CPU access – underestimate demands
6. Not understanding work loads
7. Not taking complete system into consideration
8. Lack of awareness of the dependencies
9. Lack of awareness of workload curves
Source Article: Datamation – “IT Survey Highlights Virtualization Challenges”: