Until recently, Conseco Finance Corp., like many other organizations, was struggling to find a way to control the rapid proliferation of small Intel-based servers across the company.
The systems, which were being purchased at the rate of about one per week, were being used to run a variety of very small Windows-based applications, such as domain controllers and encryption and antivirus services.
In many cases, the Intel servers that were being purchased were severely underutilized because the applications required only a fraction of the available resources, says Rod Lucero, chief IT architect at St. Paul, Minn.-based Conseco Finance.
But because of the technical challenges involved in running more than one application on a single instance of the Windows operating system, Conseco had to buy individual servers for each new application, says Lucero.
"We really wanted to find a technology that would not require us to go out and buy little pizza boxes every week," Lucero says. So nine months ago, Conseco started using virtualization technology from VMware Inc. in Palo Alto, Calif. VMware sells software-based partitioning products that allow users to take a single Intel box and carve it up into multiple smaller "virtual" servers, each of which can run a separate Windows or Linux application.
For instance, a four-processor Intel "host" box can be sliced up into 12 virtual servers for running 12 separate applications. The partitions are completely isolated from one another and can run their own copies of "guest" server operating systems such as Microsoft Corp.'s Windows 2000 Server and Advanced Server, as well as Red Hat Inc.'s Linux distribution.
VMware's software allows administrators to allocate processing power, memory and disk space as appropriate to the applications running inside each virtual partition. To an application, each virtual machine looks exactly like a physical system.
"The virtual machine is stored as a single file inside the host operating system," says Diane Greene, president of VMware. "When the guest operating system is writing to its disk, it is actually writing inside a file" on the host system, she explains.
Such capabilities have allowed Conseco to rein in Wintel server proliferation and provided for much better resource utilization, says Lucero. "We use it as a corporate standard for Windows 2000 and NT servers," he says.
"The only place where we would not use virtual servers would be for applications that have an extremely high processing requirement or absolutely need more than one processor to run," Lucero says. That's because VMware's software currently allows a maximum of only one processor to be dedicated to an application running inside a virtual partition.
So far, Conseco has created 60 virtual servers on 14 four-processor Intel machines. Each of the Intel boxes supports 8GB of memory and runs a copy of VMware's GSX software running on Red Hat Linux 7.2. Conseco has created an average of four virtual servers on each host machine. The company plans to create 135 more virtual servers on five IBM x440, eight-processor Intel servers, each with 32GB of memory and running VMware's more robust ESX technology.
Using virtual machines has allowed Conseco to save substantially on hardware, administration, backup, monitoring and office space, Lucero says. Conseco still pays license fees of $600 annually for each copy of the Windows server operating system running inside each virtual machine. And the four- and eight-processor boxes it's using to host virtual machines cost considerably more upfront than the one-processor boxes it had used.
Significant Savings
But the company has been able to consolidate and reduce most of its other costs. For instance, Conseco no longer buys separate copies of software for backing up each individual server—instead, it buys just one license for backing up the entire host box. Conseco has also been able to take the same approach with its systems management, network connectivity and server maintenance costs.
As a result, the total ownership cost of running 32 servers in a virtual machine environment is just $142,000 annually, compared with the $332,000 it would have cost to run them individually, Lucero says.
Another user who has turned to virtualization touts its value in a different situation. Since the virtual machines exist simply as disk files on the host machines, it's much easier to copy or replicate them for disaster recovery functions, says Carmine Iannace, manager of IT architecture at Welch Foods Inc. in Concord, Mass. "By virtualizing the hardware, the guest servers can operate on any box," he says.
But there are a few issues to keep in mind, Lucero says. To get optimum benefit from virtualizing your servers, it makes sense to virtualize your storage as well, Lucero says. Conseco is using storage virtualization software called SANsymphony from DataCore Software Corp. in Fort Lauderdale, Fla.
The software has allowed Conseco to create a networked storage pool from which it allocates an average of 4GB of virtual disk space to each virtual server. The approach has resulted in much more efficient use of storage resources, Lucero says. "It is also important that you really understand the memory and performance characteristics of the applications that you run on your virtual servers" to get the best performance, he says.
Running multiple applications on a single box also heightens the danger of the hardware becoming a single point of failure, says Tony Iams, an analyst at D.H. Brown Associates Inc. in Port Chester, N.Y. So it's a good idea to create online backups using VMware's snapshot functionality, he adds.
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