Database workloads are very diverse. While most database servers are lightly loaded, larger database
workloads can be resource-intensive, exhibiting high I/O rates or consuming large amounts of memory. With improvements in virtualization technology and hardware, even servers running large database workloads run well in virtual machines. Servers running Microsoft’s SQL Server, among the top database server platforms in the industry today, are no exception.
An important consideration in SQL Server consolidation scenarios is application performance when packing multiple virtual machines on a single hardware platform. Application performance in virtual machines should continue to meet or exceed required service levels. That is to say, the virtual platform should:
- Be scalable.
- Ensure that all virtual machines get resources in proportion to their load levels up to specified resource limits.
- Provide performance isolation for each virtual machine running on a host.
- Ensure that the overall load of a host will have minimal impact on the performance of applications running in individual virtual machines on that host.
We recently published a white paper, "SQL Server Workload Consolidation," that demonstrates the ability of VMware® ESX 3.5 to scale while guaranteeing fairness and isolation under a demanding SQL Server load.