Beware . . . there’s more VMware!

This week we will wrap up some of the technical delights of how VMware works and conclude with a higher-level look at where this product fits into IT operations.

On the technical side, one thing we haven’t covered is what it takes to run VMware. Because all the virtual machines are sharing the same processor there’s no such thing as too many cycles. VMware recommends you have at least a 500-MHz processor. We found that a 2.4-GHz Pentium 4 provided excellent performance.

There are a few processors not supported by VMware, including the Transmeta Crusoe, because they don’t implement “certain processor instructions.”

If you’re going to run a bunch of guest operating systems you will need lots of memory. If your host operating system is Linux you will need at the very least 64M bytes (in reality 192M bytes is more practical) plus whatever the minimum requirements are for each guest operating system running simultaneously. We ran VMware with 2G bytes of RAM and we were comfortable. The maximum memory that VMware can allocate to an individual virtual machine is 1G byte.

Obviously, you will need a graphics adapter, and VMware recommends a 16-bit display adapter. But you can squeeze by with anything greater than an eight-bit adapter. An additional requirement for Linux hosts is an X server such as XFree86 that meets the X11R6 specification.

Basic installation requires disk space, and you will need 100M bytes for Windows hosts but only 20M bytes for Linux hosts. You also will need at least 1G byte of disk space for each guest operating system (the actual disk space needed will be roughly the same as the normal requirements for installing and running each guest operating system and its applications). See VMware’s list of VMware Workstation requirements.

VMware also offers enterprise and data center-oriented products with GSX Server and ESX Server, which support partitioning and isolation of server resources with remote management and automatic provisioning.

Designed for large systems, VMware GSX Server runs on Windows 2003 Server, Web, Standard and Enterprise Editions; Windows 2000 Server, Advanced Server and Datacenter Server; and Windows NT Server 4.0. It supports up to 64G bytes of host memory, 32 host processors and 64 powered-on virtual machines, along with up to 14 virtual SCSI devices and shared cluster virtual disks up to 128G bytes in size.

Similarly scaled, the VMware ESX Server does not use a host operating system – it runs directly on the hardware and can be extended by VMware Virtual SMP, an add-on module to VMware ESX Server that lets a single virtual machine span multiple physical processors creating a symmetric multiprocessing environment.

VMware P2V Assistant is a migration tool that captures an existing operating system installation and moves it into a VMware virtual machine. This lets you migrate a working system onto any system running VMware – all VMware virtual hardware looks the same to a virtual machine.

And if you’re running a data center with ESX Servers you can use VMware VirtualCenter to pool your virtual machines into one management interface – a dashboard of virtual machines showing system availability and performance and provides automated event notifications with e-mail alerting. VirtualCenter also has integrated access control with Windows authentication.

VirtualCenter includes VMotion, which lets you migrate running virtual machines from one physical server to another on the same storage-area network without service interruption.

VMotion provides “zero-downtime maintenance” by letting you move servers without disrupting user sessions while you service the supporting hardware. The potential of these products to simplify data center operations is fantastic.

VMware Workstation is a must-have for IT and development folks.The snapshot feature makes testing on a known platform simple, and it’s nice to know that you are safe should the software in a virtual machine under VMware crash or go haywire and try to reformat every disk in sight.

VMware Workstation costs $299 as an electronic distribution and $329 as a packaged distribution, while VMware GSX Server costs $3,025 for two processors and $6,050 for four processors. Pricing for VMware VirtualCenter and ESX Server is per application.

Outstanding thoughts to gearhead@gibbs.com.