This is a follow-up to my recent blog on How VMware is Revolutionizing Data Centers. Two weeks ago at Oracle OpenWorld, I talked with one customer who detailed exactly what he's accomplished so far with VMware. A second customer explained why VMware won't help his application at all.
The first customer—who asked me to describe his company as "a large UK based Telco"—used VMware to consolidate 502 windows systems onto 25 blades. He freed 173 racks worth of space. He cut power by almost 450 KW per month and reduced his power bill by $50,000 per month, not to mention reduced service and support. In all, he expects to clear 345 racks and replace them with 20 racks, with a full return on investment in less than a year.
He runs a variety of applications: some web servers, some internal databases, some billing applications—all sorts of different stuff, mostly on Windows. On average, the systems were very lightly loaded, many at 5-10% CPU utilization or less. Some of his test and development environments run as many as 50 virtual machines on a single windows server. Production environments may run 5 or less. It all averages out to about 20. What holds the consolidation ratio down in production environments is fear of how many users a failure would affect. He expects the ratio to go up as VMware business continuance tools mature and as application administrators gain confidence.
That is the success story. The other customer explained why VMware won't help him at all. He runs a large internet site with hundreds of web servers—lots of Linux and Apache. He has a load balancing methodology that lets him saturate his servers. (In his case, the systems are actually memory limited, because they cache the most commonly used data. In other environments, CPU is the limiting factor.) He argues—correctly in my view—that VMware wouldn't help him consolidate at all, because he has no spare capacity. VMware's management capabilities could be of some use, but he already solved those problems, so he isn't looking for any help there. (Remember Tom Mendoza's rule of sales: "Customers don't open their wallets unless they are in pain." Wise salesmen save their own time, as well as their customer's.)
Server virtualization is like thin provisioning. Both allow you to hand out resources that you don't really have. With one, you hand out ten one-terabyte LUNs, even though you don't have that much real disk space. With the other, you hand out ten virtual servers even though you don't have ten real servers. (See this blog entry where I argue that thin provisioning is like writing bad checks.) Both tools help you drive up utilization, but that's only useful if utilization was previously low! If utilization was already high, there is no gain to be had. If your users immediately fill their LUNs, then you'd better have the real storage. If your applications peg their servers, then you'd better have real servers.
Thin provisioning, like VMware, performs especially well in data centers with many lightly loaded windows servers. Admins often have no idea how much storage these low-utilization apps really need, so to avoid the hassle of expanding capacity later, they request plenty extra. This leads to wasted space and low utilization. The reason customers keep talking to me about VMware is that they keep noticing the synergy between server consolidation and storage consolidation.
Here's an interesting postscript on the "large web site" customer. Two weeks ago he told me about the application that VMware won't help, but last week at a second meeting, I learned that he also has hundreds of lightly loaded Windows servers running random internal business apps. He is just starting to look into server consolidation. Ironic. My prototypical example of a customer that VMware won't help may soon be running it in a different part of his data center.
The first customer—who asked me to describe his company as "a large UK based Telco"—used VMware to consolidate 502 windows systems onto 25 blades. He freed 173 racks worth of space. He cut power by almost 450 KW per month and reduced his power bill by $50,000 per month, not to mention reduced service and support. In all, he expects to clear 345 racks and replace them with 20 racks, with a full return on investment in less than a year.
He runs a variety of applications: some web servers, some internal databases, some billing applications—all sorts of different stuff, mostly on Windows. On average, the systems were very lightly loaded, many at 5-10% CPU utilization or less. Some of his test and development environments run as many as 50 virtual machines on a single windows server. Production environments may run 5 or less. It all averages out to about 20. What holds the consolidation ratio down in production environments is fear of how many users a failure would affect. He expects the ratio to go up as VMware business continuance tools mature and as application administrators gain confidence.
That is the success story. The other customer explained why VMware won't help him at all. He runs a large internet site with hundreds of web servers—lots of Linux and Apache. He has a load balancing methodology that lets him saturate his servers. (In his case, the systems are actually memory limited, because they cache the most commonly used data. In other environments, CPU is the limiting factor.) He argues—correctly in my view—that VMware wouldn't help him consolidate at all, because he has no spare capacity. VMware's management capabilities could be of some use, but he already solved those problems, so he isn't looking for any help there. (Remember Tom Mendoza's rule of sales: "Customers don't open their wallets unless they are in pain." Wise salesmen save their own time, as well as their customer's.)
Server virtualization is like thin provisioning. Both allow you to hand out resources that you don't really have. With one, you hand out ten one-terabyte LUNs, even though you don't have that much real disk space. With the other, you hand out ten virtual servers even though you don't have ten real servers. (See this blog entry where I argue that thin provisioning is like writing bad checks.) Both tools help you drive up utilization, but that's only useful if utilization was previously low! If utilization was already high, there is no gain to be had. If your users immediately fill their LUNs, then you'd better have the real storage. If your applications peg their servers, then you'd better have real servers.
Thin provisioning, like VMware, performs especially well in data centers with many lightly loaded windows servers. Admins often have no idea how much storage these low-utilization apps really need, so to avoid the hassle of expanding capacity later, they request plenty extra. This leads to wasted space and low utilization. The reason customers keep talking to me about VMware is that they keep noticing the synergy between server consolidation and storage consolidation.
Here's an interesting postscript on the "large web site" customer. Two weeks ago he told me about the application that VMware won't help, but last week at a second meeting, I learned that he also has hundreds of lightly loaded Windows servers running random internal business apps. He is just starting to look into server consolidation. Ironic. My prototypical example of a customer that VMware won't help may soon be running it in a different part of his data center.
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