Enterprises of all sizes are building flexible storage infrastructures using Internet SCSI (iSCSI) and advanced virtualization technologies that let them allocate and shift SAN resources dynamically in response to the demands of their virtualized server environments. 

The advent of iSCSI technology, combined with the latest in server virtualization software, can offer enhanced capabilities and benefits to enterprises of all sizes. This article provides guidance on building a virtualized infrastructure with iSCSI storage arrays and virtualization software. iSCSI is a flexible and powerful storage area network (SAN) protocol that can deliver superior capabilities and benefits for enterprises of all sizes. In addition to providing enterprise-class data availability and performance, the iSCSI protocol enables breakthrough virtual storage designs that parallel the advanced designs of server virtualization technologies.

Server Virtualization and Storage Virtualization
Server virtualization is one of the most significant technology trends in IT today. Managing server hardware and software as separate infrastructure components makes it possible to significantly increase data center operating efficiencies. At a high level, server virtualization works by encapsulating guest operating systems into a set of virtual machine (VM) files. The OS and its unique execution variables and associated data sets are maintained in these files. Given sufficient memory and disk storage, a single industry-standard server running virtualization software can support many guest VMs.

Applications and data are processed in exactly the same way as in the physical environment, using the same OS facilities for making system requests. The only difference is that the OS is now a virtualized guest running in a virtual system environment. VM files can be transparently migrated from one server hardware platform to another, giving administrators the ability to allocate and shift physical server resources in response to changes in application workloads.

A scalable, highly resilient, flexible server environment is created, helping increase resource utilization and IT flexibility and reduce operating costs. Storage virtualization is typically defined as a technology that allows discrete storage systems to operate as a single resource. In light of recent advances in server virtualization, the concept of storage virtualization is being further refined as a way to create an abstraction layer between the storage hardware and logical data volumes.

Given sufficient protocol support (as with iSCSI), virtual storage products are now being designed that allow data volumes to be located and striped across multiple (and diverse) physical storage resources, including storage systems, RAID groups, disk types, and controllers. This approach not only helps increase performance and scalability, but also allows data volumes to be transparently moved from one set of resources to another without disrupting the operating systems and applications that are using the data. A scalable, highly resilient, flexible storage environment is formed, helping increase storage utilization rates and significantly reducing operating costs.