New Storage Systems

Modern storage systems are designed to handle large data volumes with reliability, scalability, and cost-effectiveness. The three significant developments are SAN, NAS, and iSCSI.

Storage Area Networks (SAN)

SAN is a high-speed dedicated network of storage devices configured as nodes, allowing flexible attachment and detachment from servers. SANs use Fibre Channel and offer many-to-many connectivity with up to 10 km server-to-storage separation.

• Pros Flexible connectivity, better isolation, nondisruptive scaling, high performance.
• Cons Multi-vendor challenges, interoperability issues, high cost, evolving standards.

Network-Attached Storage (NAS)

NAS devices are dedicated file-sharing servers that connect to existing LAN via Ethernet. They require no monitor, keyboard, or mouse, and support RAID levels 0, 1, and 5. NAS offers OS-independent file access via NFS, SMB, and FTP.

• Pros Simple setup, scalable, stores files (email, web content, backups), no downtime for upgrades.
• Cons Performance limited by network bandwidth, file-level access only (not block-level).

iSCSI Storage Systems

iSCSI sends SCSI commands over IP networks using existing Ethernet infrastructure no Fibre Channel needed. It is bidirectional, works over LANs, WANs, and the Internet, and is cost-effective for small/medium businesses.

• Pros Uses existing network cables, long-distance support, lower cost than SAN, familiar IP/Ethernet technology.
• Cons Network latency affects performance, security concerns over IP, interoperability challenges.

Comparison

Conclusion

SAN provides high-performance block-level storage via Fibre Channel for enterprise needs. NAS offers simple file-level sharing over existing LAN. iSCSI combines block-level access with cost-effective IP networking. The choice depends on performance requirements, budget, and existing infrastructure.