Storage area Network(SANs) Topics of presentation What is Storage Area Network Benefits of SAN Environment SAN Components Potential Storage Services Locations Challenges of SAN Management Ways to Manage a Storage Subsystem WORLD WIDE NAMES Simple Architecture of SAN Redundant Architecture of SAN Fibre channel vs. IP based technology Summary of RAID levels Storage services requirement

STORAGE AREA NETWORK A dedicated network that interconnects hosts and storage devices, usually via fibre channel (FC) switches and optical fiber media. A storage device is a disk sub system array with a set of disk drives. Local Area Network Fibre Channel Servers Fibre Channel Storage Area Network

Benefits of SAN Environment Storage Consolidation Concurrent Access by Multiple Hosts Use in Disaster Recovery Applications Reduced Total Cost of Ownership Reduction of management complexity/overhead Improved availability Scalability Improved data protection Increased capacity usage

SAN Components FC cable It is a high-speed data transmission technology used to connect multiple hosts and storage devices over fiber-optic or copper cables. SFP Module Small Form-Factor Pluggable (SFP) modules are transceivers that interface a motherboard with a FC cable and are used to covert electrical signals to optical signals required for fibre channel transmission to and from devices such as RAID controllers, switches and other fibre channel devices Host bus adapters (HBAs) It is also referred to as FC interface cards are installed into hosts. OS-specific device drivers are usually installed for these adapters. Storage devices RAID architecture where all disks are independently addressed. Interconnect devices such as fibre channel hubs or switches. Other special-purpose devices are SAN gateways, bridges, routers, and extenders

Potential Storage Services Locations Area of Intelligence Hardware Platform Host Servers Mainframes Fabric Appliances Switches Directors Subsystem Disks/RAIDs/Controllers Filers Tape Libraries

Challenges of SAN Management A SAN must be managed at multiple points Server OS HBA Switch Storage Array Dependencies The biggest challenge is understanding the dependencies of the various elements upon each other. Device drivers compatibility issues. Problems The new HBA has a different WWN than the old one and so zoning information in the SAN.

Ways to Manage a Storage Subsystem Out-of-Band Storage Subsystems The controllers in the storage subsystem are managed directly over the network through the Ethernet connection on each controller in the storage subsystem. In-Band Storage Subsystems The controllers in the storage subsystem are managed through an Ethernet connection on a host instead of using the Ethernet connections on each controller

WORLD WIDE NAMES It guarantees uniqueness within a large SAN fabric. There are two type of WWNs: Node WWNs—These are allocated to the entire adapter. Port WWNs—These are assigned to each port within an adapter. These are used for SAN zoning

Simple Architecture The Fibre Channel switch is an intelligent device that collects information about the SAN network topology and attached devices. Switches Enable simultaneous communication between multiple endpoints (such as a server and storage disk) Provide capabilities for managing those connections between devices so that access is controlled (through zoning) Provide physical connectivity for failover and load balancing

Redundant Architecture redundant components—controllers, switches, ports, HBAs Cabling to ensure that there is no single point of failure. No cable connection between the two switches. Switches remain independent.

Redundancy in various component Redundancy can be on host level Multiple HBA’s. Redundancy can be on switch level two or more switches. Redundancy can be on storage level ,connecting storage controller with Expansion units.

Fibre channel vs. IP based technology Servers Fibre Channel Cost and complexity Fibre Channel networking requires specialized expertise. Fibre Channel networking components are considerably more expensive than IP. Performance 4 GB Fibre Channel networking components available today Deterministic performance IP Cost and complexity Ethernet and TC/IP networking technologies are familiar. Ethernet networking components are less expensive. One networking technology to network clients, servers, and storage. Performance 1 GB Ethernet networking components available today Not ideal for SAN solution Fabric devices Storage arrays

RAID levels RAID 0 is the fastest and most efficient array type but offers no data redundancy or fault-tolerance. RAID 1 is the array technique of choice for performance-critical, fault-tolerant environments and is the only choice for fault-tolerance if no more than two drives are available. RAID 3 is a popular choice for data-intensive or single-user applications that access long sequential records. However, it does not typically allow multiple I/O operations to be overlapped. RAID 5 is generally the best choice for multi-user environments that are not particularly sensitive to write performance. At least three, and typically five or more drives are required to build a RAID 5 array.

Storage services requirement Manageability Performance Capacity Security Recoverability Availability Storage services require scalability in Size Speed number of nodes Distance throughput Reach

SAN Environment in NUST DATACENTER Hosts IBM Xseries 346 2 Switch Brocade ibm 2005-H16 1 Storage controller Ibm Ds 4300 HBA Qlogic 2340 XSeries 346 Qlogic 2340 Brocade ibm 2005-H16

Enterprise Management Window The Enterprise Management Window (EMW) provides high-level management of storage system