Knowing when to deploy DAS NAS and SAN can optimize t Availability t Scalability t Performance t Manageability t Cost effectiveness

DAS, NAS, FC-SAN, E-SAN t Coexistent architectures t DAS- Based on weak storage industry standards t NAS- Based on strong network industry standards t FC-SAN- SNIA standards will not happen this year t E-SAN - No standards yet and unsolved problems t Appropriate Applications for each t Four Choices in NAS

Location of the Network Determines the Architecture

OSI Communication layers

Network Protocols

Frames contain ‘nested’ packets

IP Packets can contain block requests or NFS/CIFS file requests

DAS = Direct Attached Storage t Evolved from the Storage Industry t 95% of all storage sold today t 7 Major variations of SCSI t Many implementations of FC t Host file systems request blocks of data with SCSI or FC commands t Data is returned over SCSI buses or FC loops

DAS Topology

A Performance Critical Customer Reservation System

NAS = Network Attached Storage t Based on strong remote file system standards like NFS and CIFS t Uses strong network standards for file requests and data t Pioneered by Auspex t Predicted by IDC to grow from $1.7 B to $6.6B in three years or 67% per year. t Outboard File System can be Fat or Thin t Networks offer security and congestion control unlike FC-SAN t Necessary for NFS/CIFS file sharing

NAS Topology

NAS NFS and CIFS Sharing A UNIX-based document control database accessed by NT clients in purchasing

Distributed Storage before NAS Consolidation

Distributed Storage after NAS Consolidation

Technical NAS Applications MCAD, ECAD, software development or geoseismic applications

Internet Applications Optimized for DAS and NAS

FC-SAN = Fibre Channel SAN t SAN means FC-SAN to most folks t “Hot” topic - yet misunderstood t 7%-10% of shops in production t Vision is heterogeneous t Reality is homogeneous [proprietary] t EMC = ESN, Compaq=ENSA, HDS=FDN t Security Risks without standards t Bottlenecks without standards t Heterogeneous switch interoperability is the main problem today

Heterogeneous FC-SAN Vision

Homogeneous FC-SAN Reality

FC-SAN Link and Node Congestion

Deterrents to FC-SAN today t Source: Computerworld August 7, Based on a recent survey of 100 IT professionals aware of FC-SAN first hand.

E-SAN = Ethernet SAN t Where block requests are sent over IP t iSCSI proposed by CISCO/IBM to IETP t 3ware’s Storage Control Protocol (SCP) over TCP uses non-SCSI commands t SCSI over UDP (SoIP) proposed by Nishan t Adaptec is proposing a new transport layer especially designed for SCSI transport over IP

FC switch vendors fight back by encapsulating FC commands over IP t Cisco and Brocade plan to encapsulate FC over TCP/IP t FCIP is being proposed by Gadzoox and Lucent for long distance WAN / MAN / SAN implementations. t This may lead to FC-SANs interconnected in long distance E-SANs

Why the Fibre Channel people are worried

Summary t The location of the network determines the architecture t DAS, FC-SAN, E-SAN = blocks / data t NAS = file requests / data t Coexistent architectures t Only NAS is based on strong network industry & remote file system standards t Only proprietary FC-SANs control the security risks and bottlenecks of FC t E-SAN is emerging with performance and standards problems to be solved