Oracle RAC on vSphere 4.1 (if you can virtualize this, you can virtualize anything!)
For those who have been following Blue Shift, it’s no secret that one of my favorite blogs is VMWare’s VROOM! and there’s several reasons for this.
Many of us have been in a situation where someone has told us “you can’t virtualize that!” and often the only options are to either go ahead and demonstrate by attempting to virtualize it (often not an option), or to provide a real world case study of someone who has. Proving that applications can be virtualized is often critical for putting organizations into position to realize additional benefits of the private cloud including reduced OPEX and increased agility.
Oracle RAC is one of those holdouts for virtualization for two key reasons (I think). One reason deals with vendor support and while this has been an issue in the past, Oracle RAC is now supported under vSphere (that’s not to say that licensing and other improvements are not still needed). A second reason is that Oracle RAC is a larger and often very intense workload and the perception lingers in some circles that performance of Oracle RAC would suffer too much if virtualized.
Frank Sinatra sings in “New York, New York” that “if you can make it here, you can make it anywhere”. Well to a large extent, if you can virtualize Oracle RAC, you can virtualize most any x86 workload. So how does Oracle RAC perform under vSphere 4.1? Let’s take a look at what the VROOM! Blog found.
For the test lab, two Oracle RAC configurations were used – one physical and one virtual. The exact same hardware was used in each configuration (the servers were dual booted between RHEL and ESX).
After some configuration as detailed in the blog post, the testers found that the virtualized Oracle RAC instance performed 11 to 13 percent slower than the native physical environment:
If you think 11 to 13 percent is a lot, let’s pause for a second. These metrics were based on Orders Per Minute (OPM) as well as Response Time. For what percentage of the day are your Oracle RAC servers at 85% of OPM capacity? Chances are you’re servers (hopefully) aren’t running quite that hot. The CPU load of the physical hosts and the VM’s was more than 95% during these tests. So when the statement is made that the virtualized environment was 11-13% slower, this performance difference only applies to a stress test (CPU >95% scenario) and normal operating performance will likely be significantly better.
But even if one assumes the worst case of 13% performance degradation, this would still be an acceptable trade off in many datacenters to get to the point where the operational benefits of virtualization (DR, agility, private cloud) can be realized.
Still not convinced? How about listening to a real live customer share their Oracle RAC on vSphere experiences? On January 25 VMware will be hosting a webcast where IPC (The Hospitalist Company) will share their experiences with successfully virtualizing Oracle RAC on vSphere and addressing issues such as support, performance, and cost savings.
There’s very few x86 workloads that can’t be effectively virtualized and Oracle RAC can certainly be virtualized effectively in many environments.