in order to function. An interesting trend in the industry is the move toward the virtualization switch. This is fast- switching network equipment that can provide storage virtualization at wire speeds without notice- able latency. A couple of companies with interesting technology are already active in this field, such as Maranti Networks, Pirus Networks, and SO on. Storage virtualization purports to offer organizations and enterprises an unprecedented value by ensuring access to their vast data without worrying about which system, what location, which format, or which operating system platform they are stored in. However, the very same abstraction layer that it provides from the actual underlying hardware may end up hurting the driving business application. This is because numerous commercially available data management applications take advantage of Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. STORAGE NETWORK PROCESSORS (SNPS) 202 NETWORK PROCESSORS advanced hardware features to provide high value to their users by implementing sophisticated func- tions linked to the actual hardware, such as autoconfigure or autodiscover. By its mere dependence on this abstraction layer, storage virtualization may lose the capability to offer this type of sophisti- cation unless the industry comes up with new ideas about how to handle this problem. However, for the moment, we cannot have our cake and eat it too. iSCSI The extraordinary advantage of iSCSI is that it provides access to and from block-level storage devices, such as disk arrays, single disks, tape drives, and libraries, directly over regular TCP/IP networks. Before the arrival of iSCSI, all TCP/IP-based access to networked storage in the form of NFS and CIFS servers occurred in the framework of NAS systems, which have always required TCP/IP host-to-host data transfers. The ramifications of 