Guest Blog: SQL Server Consolidation with Microsoft Virtualization

Hello, my name is Vipul Shah and I’m a Senior Product Manager with the Virtualization Team.

Due to its ability to drive down costs and drive up resource usage, Microsoft SQL Server consolidation is top of mind for our customers these days. Microsoft virtualization, which includes Windows Server 2008 R2 Hyper-V and System Center, is one of the well known mechanisms to enable this. Today, Ted Kummert, Senior Vice President, Microsoft Business Platform Division , released a video (click here) that outlines how virtualization enables consolidation.

So the natural question is – can we achieve higher amounts of throughput as we consolidate? Can we improve the throughput with recent advances in hardware and the recent release of Windows Server 2008 R2 Hyper-V?

To address this, we recently performed tests that are discussed in the Best Practices for SQL Server Virtualization webcast (click here) and in the SQL Server Consolidation Guidance (click here).

In our tests, we ran a complex stock trading application workload on servers with Second Level Address Translation (SLAT). In physical environments, the operating system translates virtual memory addresses to physical addresses. However with virtualization, we have an additional translation (the second level address translation) because you are running operating systems within virtual machines. This means additional CPU cycles are spent doing this translation. The SLAT enabled processors complete this translation within the silicon, leading to performance advantage compared with non-SLAT enabled CPUs. You get these processors from both Intel and AMD.

We chose a 16-core HP DL585 server with SLAT-enabled AMD processors with HP EVA 8000 storage running Windows Server 2008 R2 Hyper-V. We created virtual machines (VM) each with 4 virtual processors and 7 GB RAM using a fixed-sized VHD format. We started to run our workload with one VM and gradually increased the load, adding more VMs as we went along. We found that we were able to increase the throughput with consolidation. The workload scaled near-linearly up to 4 VMs consuming all of the physical cores on the server (16 cores total). Then we added even more VMs, consolidating up to 8 VMs. We over-committed virtual-processors to physical-cores ratio by 2:1. We were able to run heavy load (3000 batch requests per second), consuming about 70% CPU on the server. The tests also found that Windows Server 2008 R2 offered improved performance than the prior release as shown by the dotted red-line in the graph.

Microsoft virtualization (Hyper-V and System Center) combined with advances in hardware technology (such as SLAT-enabled technology) can provide a solid consolidation platform for production workloads using SQL Server.

Microsoft continues to work with partners to offer solutions that help our customers realize the benefits of virtualization (click here). Further guidance from our partners will be forthcoming. For more resources on virtualizing Microsoft server applications, click here.

Vipul Shah

Microsoft Virtualization Team, Senior Product Manager