Many of VMware’s customers use memory reservations during troubleshooting only in a final attempt to fix performance problems. It is true that memory reservations can limit ballooning and host swapping. But if you are only using reservations to anticipate and avoid memory bottlenecks, you are missing one of the great uses of the feature: memory reservations can drive over-commitment.
Memory Reservations Drive Over-commit
March 31st, 2010
Mar, 31 2010
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Optimal Web Servers: vSphere Required
March 22nd, 2010
Mar, 22 2010
Just over a year ago VMware set a world record for web server performance on 16-core systems. The reason ESX beat native performance is its excellent scalability when compared to the poor scalability of commercial web servers. By implementing multiple web servers in virtual machines on a single host, VMware can drive more web transactions through the host than possible without ESX present. Today I want to update everyone on our work with virtual web servers and repeat my plea: virtualize your web servers now!
vSphere 4.0, Hyper-Threading, and Terminal Services
March 17th, 2010
Mar, 17 2010
I recently wrote a blog article detailing Hyper-Threading (HT) and its effect on vSphere. An astute reader pointed out, a recent update to Project VRC‘s terminal services analysis suggests disappointment with HT on vSphere. We spent a lot of time looking at those results to understand why they contradicted the body of performance data, which show HT offering 10-30% gain on vSphere. What we discovered led us to create a vSphere patch that would allow users to improve performance in some benchmarking environments.
Hyper-Threading on vSphere
March 6th, 2010
Mar, 06 2010
I continue to receive many questions from our customers on the expected performance gains of the new version of Hyper-Threading in Intel’s Core i7 processors. The answer requires a little bit of discussion on Hyper-Threading, a little bit on ESX, and comes with some performance data. If you are still interested, read on.
Maximum Concurrent VMotions
March 3rd, 2010
Mar, 03 2010
A VMware customer and attendee of a talk I gave at a performance roundtable asked me for a preview of unreleased features*. When I talked about the amazing improvements to VMotion that would enable as many as eight concurrent VMotions the customer said, and I am paraphrasing here, “Yawn. I can already do that.” Really? I had no idea customers could do this. As it turns out, many of us at VMware did not know that customers knew how to do this.
Memory Compression
March 1st, 2010
Mar, 01 2010
Steve Herrod’s keynote at Partner Exchange 2010 included a tantalizing slide on an upcoming memory maximization technology: memory compression. A few of you have already seen the overview of this technology Kit Colbert and Fei Guo previewed it at VMworld 2009. Today I want to tell you how this upcoming feature will help you pack even more virtual machines onto your existing servers.