iSCSI-Unified Network Storage Increases the Cost-Effectiveness of the Distributed Info Value Chain

All applications are insulated from dealing directly with the disk drives. The Server’s operating system
incurs the overhead of the entire flow and management disk I/O. It provides the physical disk translation through its local file system and logical volume management through a volume manager.

DAS works well in environments with a limited number of servers. However, if there are dozens of servers and significant data growth, the situation rapidly becomes unmanageable. The storage for each server has to be managed separately and can’t be easily shared. Scalability is limited, and the overall efficiency of the DAS resource tends to be diminished.

With the varied data management needs of today's business functions, enterprises have recognized the need to take a more cost-effective, flexible, and scalable networked storage approach for their valuable highvolume information.

Storage Area Networks

In a storage area network (SAN), a number of servers have access to a pool of storage resources. Each server utilizes a portion of the storage yet does not know about the other server’s data, so the servers share the storage and not the data. The servers are connected via host bus adapters (HBAs) to Fibre Channel switches, which in turn are connected to the Fibre Channel storage system(s). The servers and storage communicate via the Fibre Channel protocol suite, which allows SCSI commands to be transmitted via serial connections. The Fibre Channel interface and protocol allow for high throughput, and are typically only used in the most elite and demanding performance applications. Component costs are high and complexity of maintenance can make SAN implementations an undesirable choice.