Moving Towards SAN Storage: An Enterprise Perspective

One of the major components of any enterprise IT infrastructure is data storage. There has been continuous effort to explore new storage technologies to improve performance with respect to input/output operations, data availability, consolidation of storage assets and data protection and archiving. Storage has moved from the traditional Direct Attached Storage (DAS) to Network Attached Storage (NAS) and now to Storage Area Networks (SAN). Traditional storage subsystems like Server Attached Storage (SAS) and Network Attached Storage (NAS) use disks directly attached to servers over a Small Computer Systems Interface (SCSI) bus. However, these have limited capabilities keeping in view the rapidly expanding storage needs. The SAN technology holds great promises to be used for enterprises where issues like data availability, serviceability, consolidation of storage and reliability are major concerns. It can provide high speed data transfer with many other storage services, backboned with a high speed Fibre Channel (FC). Storage-area networks are also more popular and efficient way of building large storage systems both in an enterprise environment and for multi-domain storage service providers. SAN design and implementation requires careful analysis before SAN can be used as an enterprise storage solution. In this paper we provide an overview of SAN technology from the view point of building large storage systems in an enterprise environment. We also discuss on return on investment (ROI) which can justify the adoption of SAN in an enterprise. Further, it compares two specific technologies, namely, FC SAN and IP SAN. In the sequel different design considerations are made to recommend suitable SAN implementations in order to meet the requirements of any enterprise.