© 2009 IBM Corporation Statements of IBM future plans and directions are provided for information purposes only. Plans and direction are subject to change without notice. DAS, NAS and SAN Ryan Leonard Storage and Solutions Architect

Statements of IBM future plans and directions are provided for information purposes only. Plans and direction are subject to change without notice. System Storage July 2009 Agenda  DAS, NAS, and SAN  SAN host interfaces –SAS –iSCSI –FC

Statements of IBM future plans and directions are provided for information purposes only. Plans and direction are subject to change without notice. System Storage July categories of external storage  DAS –Direct-attached storage device –Generally attached / dedicated to a specific server  NAS –Network-attached storage –Connected to a server via a network –Can be shared or dedicated  SAN –Storage Area Network –Connected to server via a storage network –Can be shared or dedicated Server AServer BServer C JBOD AJBOD BJBOD C Ethernet Server AServer BServer C NAS Ethernet Server AServer BServer C SAN Ethernet

Statements of IBM future plans and directions are provided for information purposes only. Plans and direction are subject to change without notice. System Storage July 2009 Why use either a SAN or NAS?  Why consolidate anything? –Let’s consider an analogy  Greater efficiency  Simplified management  Increased utilization  Reduced cost  Leverage features

Statements of IBM future plans and directions are provided for information purposes only. Plans and direction are subject to change without notice. System Storage July 2009 NAS detail  NAS –Provides file-level access to storage Ethernet connectivity / TCP/IP CIFS (Common Internet File System) NFS (Network File System) –Networked file system allows for concurrent access to data –Several layers between data request and receipt Server DataNIC Storage controllerNAS NFS/CIFS TCP/IP HBA Disk(s)

Statements of IBM future plans and directions are provided for information purposes only. Plans and direction are subject to change without notice. System Storage July 2009 SAN detail  SAN –Provides block-level access to storage Ethernet (iSCSI) Fibre Channel –Concurrent access generally not allowed to specific datasets –Remote disk(s) appear as locally attached block devices to server Server DataHBA Storage controller Disk(s)

Statements of IBM future plans and directions are provided for information purposes only. Plans and direction are subject to change without notice. System Storage July 2009 Interface Options  Serial attached SCSI (SAS)  iSCSI  Fibre Channel (FC)

Statements of IBM future plans and directions are provided for information purposes only. Plans and direction are subject to change without notice. System Storage July 2009  SAS – Serial Attached SCSI –A serial communication protocol designed for transfer of SCSI commands and data to and from devices over point-to-point interconnections  Key Benefits –New roadmap with industry-wide acceptance –Significant performance enhancements 3-Gbps SAS x4 “wide” ports –Cost equivalent to parallel SCSI –Freedom from 15 drive maximum per SCSI channel SAS Basics and Benefits

Statements of IBM future plans and directions are provided for information purposes only. Plans and direction are subject to change without notice. System Storage July 2009 SAS Special Considerations  Distance limitations – 8 meters per discreet connection  Perceived complexity based on the newness of the technology  SAS expanders, which will support SAN-like capabilities for SAS, are still in development  Limited to the number of servers that can be attached – based on the number of SAS host ports on the storage system

Statements of IBM future plans and directions are provided for information purposes only. Plans and direction are subject to change without notice. System Storage July 2009 SAS Positioning  Excellent solution for directly attaching one to three local servers to a single storage device –Cost-effectively facilitates one-room storage configurations –Offers outstanding performance –No networking expertise necessary – removes complexity –Low cost and simple to use –High bandwidth and low latency

Statements of IBM future plans and directions are provided for information purposes only. Plans and direction are subject to change without notice. System Storage July 2009 iSCSI Basics and Benefits  iSCSI - internet Small Computer System Interface –A network protocol that enables transmission of SCSI commands and data over an IP-based network usually via an Ethernet interface  Key Benefits: –Low cost –Less complexity Extensive knowledge base – expertise in every IT organization –Flexible configuration topologies –Extensive reach with no distance limitations –Future performance 1Gb/s today with roadmap for 10Gb/s and beyond

Statements of IBM future plans and directions are provided for information purposes only. Plans and direction are subject to change without notice. System Storage July 2009 iSCSI Special Considerations  Network congestion risks the dropping of frames – important to evaluate configuration to foresee any bottlenecks  Achievable performance is misunderstood –Hardware and connection parameters can be leveraged to achieve desired performance  Security at risk when sharing IP storage networks with the existing network –Separate storage traffic from normal LAN traffic  Disparate expertise and confusion over storage and networking IT roles

Statements of IBM future plans and directions are provided for information purposes only. Plans and direction are subject to change without notice. System Storage July 2009 iSCSI Positioning  Interface of choice for entry-level and SMB storage networks where FC is cost prohibitive –iSCSI has turned the corner, with a large number of installations in companies of all sizes –Users are growing more familiar with the lower-cost alternative to FC –Reach – IP SANs can to be located virtually anywhere. –Minimal storage investment – utilize existing IP SAN and additional equipment is relatively inexpensive –Leverage existing IT resources – in-house IP expertise –Simplify installation and management – a mature technology with proven management tools can be easily facilitated –Extend shared storage benefits to all servers – with minimal per-server connectivity costs

Statements of IBM future plans and directions are provided for information purposes only. Plans and direction are subject to change without notice. System Storage July 2009 FC Basics and Benefits  FC – Fibre Channel –A serial networking interface that supports the transmission of upper level protocols – including SCSI command sets and data – over fiber optic or copper cables  Key Benefits –Scalable – supports up to 16 million addresses. –Distance – 10,000 meters maximum cabling length –High bandwidth – low latency and high IOPs –Investment protection – auto-negotiating link speeds allowing for seamless integration into an existing 1Gb/s or 2 Gb/s environment –Congestion free with credit-based flow control delivering data as fast as the destination buffer is able to receive it.

Statements of IBM future plans and directions are provided for information purposes only. Plans and direction are subject to change without notice. System Storage July 2009 FC Special Considerations  Steep learning curve for administrators unfamiliar with deployment and management  Expensive and complex –Costly FC SAN equipment and maintenance –Training personnel internally or hiring a service company is a significant addition to TCO  Low-cost servers will typically not be included as the investment to attach it can outweigh the cost of the server itself – does not always make financial sense to deploy

Statements of IBM future plans and directions are provided for information purposes only. Plans and direction are subject to change without notice. System Storage July 2009  Dominates SANs today and expected to retain dominance in the enterprise market –FC will maintain advantages in both performance and scalability –Most mature and time-proven designs –High addressability necessary for large customers with thousands of servers –Takes the fullest advantage of server clusters 4, 8, 16 and up to 100 or more servers as needed –Data integrity – class of service settings guarantees delivery of frames FC Positioning

Statements of IBM future plans and directions are provided for information purposes only. Plans and direction are subject to change without notice. System Storage July 2009 To simplify… Performance ScalabilityCost SASFC iSCSI  Pick 2…

Statements of IBM future plans and directions are provided for information purposes only. Plans and direction are subject to change without notice. System Storage July 2009 Summary  DAS, NAS, and SAN have intrinsic differences –Cost –Performance –Ease of management  SAS, iSCSI, and FC –Cost vs. scalability vs. performance