Virtualization is a sea change from the days of one image per physical machine. And the benefits are clear, from better hardware utilization to lower costs to easier management. But while the resulting server consolidation is a good thing, it only solves half the problem. You still need to ensure that best-practice storage management is available to both your physical and virtual servers.
COFFEE BREAK
VIRTUAL SERVERS NEED VIRTUAL STORAGE
SANs provide transparent Consolidation is a common trend in many IT environments, providing benefits such asmovement of applications improved hardware resource utilization, easier management, and lower costs. For across your enterprise without storage, consolidation is accomplished by moving data off of direct attached storagethe hassles of reinstallation, (DAS) inside the server onto a shared pool of storage in a storage area network (SAN).copying, or reconfiguration, Recently, server consolidation has become popular thanks to technologies likeresulting in flexibility, improved ® ® TMicrosoft Virtual Server 2005 and VMware products ESX Server and VMwareresource utilization, and Tlower costs. Server . These "virtual machine" resources enable you to consolidate server images onfewer hardware platforms to improve IT efficiency.
MAKING THE BEST OF A COMPLEX SITUATIONIt's easy to see the advantage of consolidating servers. In today's IT environment, you're likely to run numerous applications on many operatingsystems (OSs) - and until recently, the easiest way was to run each appli-cation on different server hardware. The drawback was low server utilizationrates. If each physical server is responsible for its own application, serverutilization rates often run about 30% - leaving 70% of the server unused. Ifyou have 100 servers at 30% utilization, you could improve utilization byremoving 50 applications from their own servers and placing them on top ofthe other 50 servers, giving you 60% utilization. CIOs and business man-agers wonder why they have to buy and operate so many servers whenthere's plenty of unused capacity already deployed. Fewer physicalmachines would reduce both capital expense and staffing costs.
There are good reasons behind IT's deployment methods. Because expansion of server resources for a deployed application is painful, time consuming, and requiresdowntime, it is often easier to use individual servers for new applications than to try toconfigure servers with multiple applications to effectively use capacity, and then have todeal with workload changes that cause later re-deployment. Low utilization rates meantat least you had a place for the application to grow easily and avoid additional IT burden and application downtime. It might not be what you really wanted, but it was thebest choice at the time.
VIRTUAL SERVERS - AT LAST, PORTABILITYWith virtual server technologies, encapsulation and movement of both operating envi-ronments and applications is easy. Now you can consolidate servers and gain flexibilityrather than IT headaches. Operating system images and applications are now portablebetween physical machines rather than wedded to hardware, SAN environments add flexibility and eliminate most datayet each virtual server main- copying, but administrators still have to deal with storageGuard against implementing a tains its identity to clients. load balancing and scaling tasks - which still require down-solution that only solves half the By virtualizing server hard- time. To provide the most flexible and fluid implementation,problem - if you consolidate ware, network configura- virtual servers need virtual SAN storage with automatic loadservers and storage, ensure thatbest-practice storage manage- tions, OS, and application balancing.ment is available to both your configurations, this technol-physical and virtual servers. ogy allows transparent SELECTING VIRTUALIZATION TECHNOLOGIESmovement. With Microsoft Since virtual server and SAN technologies vary, be sure toVirtual Server 2005 or select the solution that offers all the functionality you need.VMware, you can run multiple OSs and For example, it's important that the virtual machines be applications as smaller units that are encapsulated. It's as if "SAN aware" - if the virtual machines "know" they are on theyou have a "handle" to pick up an OS and application and SAN, then SAN-based functions such as snapshot-basedmove it to another server hardware system with minimum backups, Multi-Path I/O, cluster support, and SAN bootingdisruption. Now, moving a virtual machine is simple: will be available. If not, the virtual machines will "believe" they1. In a SAN environment: Copy a configuration file, pause are on DAS, and m... [download for more]
