Chapter 6

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Storage Area NetworkStorage Area Network

Chapter 6

Section 2 : Storage Networking Technologies and Virtualization


Chapter Objectives

Upon completion of this chapter, you will be able to:

o Describe SAN and its benefits

o Discuss components of SAN

o Describe connectivity options of SAN

o Describe FC protocol stack and FC addressing

o List common FC topologies


Lesson - Fibre Channel SAN

Upon completion of this lesson, you will be able to:

o Define Storage Area Network and its benefits

o Define Fibre Channel

o List the component of SAN

o Describe three FC interconnectivity options

o List different FC port types


Business Needs and Technology Challenges

o Just-in-time information to business users

o Integration of information infrastructure with business processes

o Flexible and resilient storage architecture

o DAS is inefficient to meet these challengeso Storage Networking emerged as a solution

o FC SANo NASo IP SAN


What is a SAN ?

o Dedicated high speed network of servers and shared storage devices

o Provide block level data access

o Resource Consolidation o Centralized storage and management

o Scalabilityo Theoretical limit: Appx. 15 million devices

o Secure Access

Storage ArrayStorage Array

Servers

FC SAN

Additional Task

Research on Bladed Switch

Technology


Understanding Fibre Channel

o Fibre Channel is a high-speed network technology that uses:o Optical fiber cables (for front end connectivity)o Serial copper cables (for back end connectivity)

o Latest FC implementations support 8Gb/s

Users andApplication

Clients

Storage andApplication

Data

Servers and Applications

FC SANIPnetwork

o Servers are attached to 2 distinct networks


FC SAN Evolution

SAN Islands FC Arbitrated Loop

Storage Array

Interconnected SANsFC Switched Fabric

Enterprise SANsFC Switched Fabric

Fibre Channel SAN Evolution

Server

FC SwitchFC Switch

FC Switch FC Switch

FC Switch

Servers

Storage Arrays

FC Switch

FC Switch

FC Hub

FC Hub

Servers

Storage Arrays


Components of SAN: Node portso Examples of nodes

o Hosts, storage and tape library

o Ports are available on:o HBA in hosto Front-end adapters in storageo Each port has transmit (Tx) link and

receive (Rx) link

o HBAs perform low-level interface functions automatically to minimize impact on host performance

Link

Port 0 RxTx

Node

Port 0

Port 1

Port n


Components of SAN: Cablingo SAN implementation uses:

o Copper cables for short distanceo Optical fiber cables for long distance

o Two types of optical cableso Single-mode

o Can carry single beams of lighto Distance up to 10 KM

o Multi-modeo Can carry multiple beams of light

simultaneouslyo Distance up to 500 meters


Components of SAN: Cabling (Connectors)

Node Connectors:

o SC Duplex Connectors

o LC Duplex Connectors

Patch panel Connectors

o ST Simplex Connectors

ST Connector

LC Connector

SC Connector


Components of SAN: Interconnecting deviceso Basis for SAN communication

o Hubso Switches ando Directors

FC HUB FC Switch

Director


Components of SAN: Storage arrayo Provides storage consolidation and

centralization

o Features of an arrayo High Availability/Redundancyo Performanceo Business Continuityo Multiple host connect

Servers

Arrays

FC SANHBA

HBA

HBA


Components of SAN: SAN management softwareo A suite of tools used in a SAN to

manage the interface between host and storage arrays

o Provides integrated management of SAN environment

o Web based GUI or CLI


SAN Interconnectivity Options: Point to Point

Point to point (Pt-to-Pt)o Direct connection between deviceso Limited connectivity

Servers

Storage Array


SAN Interconnectivity Options: FC-AL

o Fibre Channel Arbitrated Loop (FC-AL)o Devices must arbitrate to gain controlo Devices are connected via hubso Supports up to 127 devices

Servers

Storage ArrayFC Hub


FC-AL Transmission

Transmit

Transmit

Receive

Receive

Receive

Transmit

Receive

Transmit

Byp

Byp

Byp

Byp

Hub_Pt Hub_Pt

Hub_Pt Hub_Pt

Node A

Node B Node C

Node D

Byp

Byp

NL_Port #4

HBA

NL_Port #4

Array Port

NL_Port #1

HBA

NL_Port #1

HBA

NL_Port #3

FA

NL_Port #3

HBA

NL_Port #2

HBA

NL_Port #2

HBA

Byp

Byp


SAN Interconnectivity Options: FC-SW

o Fabric connect (FC-SW)o Dedicated bandwidth between deviceso Support up to 15 million deviceso Higher availability than hubs

Servers

Storage Array


Port

FC-SW Transmission

Transmit

Transmit

Receive

Receive

Receive

Transmit

Receive

Transmit

NL_Port #1

HBA

NL_Port #4

HBA

NL_Port #2

HBA

N_Port #1

HBA

Port

N_Port #4

HBA

N_Port #2

Storage Port

Port

Port

Node A

Node B Node C

Node D

N_Port #3

Storage Port


Port Types

Host

N-Port

FC Switch

F-Port

Tape Library

Host

HostFC Hub

FL-Port

NL-Port

NL-Port

NL-Port

FC Switch

Storage Array

N-Port

F-PortE-Port E-Port

Storage Array

N-Port

F-Port

?? ?

?

? ?

?

?

? ?

??


Inter Switch Links (ISL)

o ISL connects two or more FC switches to each other using E-Ports

o ISLs are used to transfer host-to-storage data as well as the fabric management traffic from one switch to another

o ISL is also one of the scaling mechanisms in SAN connectivity

Multimode Fiber

1Gb=500m 2Gb=300m

Single-mode Fiber

up to10 km

FC Switch

FC SwitchFC Switch

FC Switch


Login Types in a Switched Network

Extended Link Services that are defined in the standards:

o FLOGI - Fabric logino Between N_Port to F_Port

o PLOGI - Port logino Between N_Port to N_Porto N_Port establishes a session with another N_Port

o PRLI - Process logino Between N_Port to N_Porto To share information about the upper layer protocol type in useo And recognizing device as the SCSI initiator, or target


Lesson Summary

Key topics covered in this lesson:

o FC SAN and its components

o SAN Interconnectivity Options

o Port types and inter switch links

Additional Task

Research on working of

FC Hub & Switch

Additional Task

Research on concept of channel &

network Technology


Lesson: Fibre Channel Architecture


o Describe layers of FC

o Describe FC protocol stack

o Discuss FC addressing

o Define WWN addressing

o Discuss structure and organization of FC Data

Additional Task

Research on Flow Control & Class

of FC Services


FC Architecture Overview

o FC uses channel technology

o Provide high performance with low protocol overheads

o FCP is SCSI-3 over FC networko Sustained transmission bandwidth over long distanceso Provides speeds up to 8 Gb/s (8 GFC)

o FCP has five layers:o FC-4 o FC-2 o FC-1 o FC-0 *FC-3 is not yet implemented 1 Gb/s 2 Gb/s 4 Gb/s 8 Gb/s

FC-4

FC-2

FC-1

FC-0

Application

SCSI HIPPI ESCON ATM IP

Framing/Flow Control

Encode/Decode


Fibre Channel Protocol StackFC layer Function SAN relevant features specified by FC layer

FC-4 Mapping interface

Mapping upper layer protocol (e.g. SCSI-3 to FC transport

FC-3 Common services Not implemented

FC-2 Routing, flow control

Frame structure, ports, FC addressing, buffer credits

FC-1 Encode/decode 8b/10b encoding, bit and frame synchronization

FC-0 Physical layer Media, cables, connector


Fibre Channel Addressing

o FC Address is assigned during Fabric Logino Used to communicate between nodes within SANo Similar in functionality to an IP address on NICs

o Address Format:o 24 bit address, dynamically assignedo Contents of the three bytes depend on the type of N-Porto For an N_Port or a public NL_Port:

o switch maintains mapping of WWN to FC-Address via the Name Server


World Wide Names

o Unique 64 bit identifier

o Static to the porto Used to physically identify ports or nodes within SANo Similar to NIC’s MAC address

World Wide Name - Array

50101

00000

00000

60110

00000

10001

60110

00000

00000

00000

60110

00000

00000

10001

B1011

20010

Company ID24 bits

Port Model Seed32 bits

World Wide Name - HBA

1 0 0 0 0 0 0 0 c 9 2 0 d c 4 0

Reserved12 bits

Company ID24 bits

Company Specific24 bits


Structure and Organization of FC Datao FC data is organized as:

o Exchange operationso Enables two N_ports to identify and

manage a set of information unitso Maps to sequence

o Sequenceo Contiguous set of frames sent from one

port to another

o Frameso Fundamental unit of data transfero Each frame can contain up to 2112 bytes

of payload

SOF4 Bytes

Data Field0 - 2112 Bytes

CRC4 Bytes

EOF4 Bytes

Frame Header24 Bytes


Lesson Summary


o Fibre Channel Protocol Stack

o Fibre Channel Addressing

o Data Organization: Frame, Sequence and Exchange


Lesson: FC Topologies and Management


o Define FC fabric topologies

o Describe different types of zoning


Fabric Topology: Core-Edge Fabrico Can be two or three tiers

o Single Core Tiero One or two Edge Tiers

o In a two tier topology, storage is usually connected to the Core

o Benefitso High Availabilityo Medium Scalabilityo Medium to maximum Connectivity

Single-core topology

Dual-core topology

FC Switch FC Switch FC Switch

Storage Array

DirectorCore Tier

Edge Tier

FC Switch FC Switch FC Switch

Storage Array

DirectorCore Tier

Edge Tier

DirectorServer

Server


Fabric Topology: Mesh

o Can be either partial or full mesh

o All switches are connected to each other

o Host and Storage can be located anywhere in the fabric

o Host and Storage can be localized to a single switch

Server

FC Switches

Partial Mesh

Storage Array

Server

FC Switches

Full Mesh

Storage Array


Fabric Management: Zoning

Storage Array

FC SAN

Servers

Array port

HBA


Zoning Components

Zone set

Zone Zone Zone

Member Member Member Member Member Member

Zone sets

(Library)

Zone

(Library)

Member

WWN's


Types of Zoning

Zone 2

Zone 1

Zone 3

Port 7

Port 9

Port 1

Port 5

WWN 10:00:00:00:C9:20:DC:40

WWN 10:00:00:00:C9:20:DC:56

WWN 10:00:00:00:C9:20:DC:82

WWN 50:06:04:82:E8:91:2B:9E

Zone 1 (WWN Zone) = 10:00:00:00:C9:20:DC:82 ; 50:06:04:82:E8:91:2B:9EZone 2 (Port Zone) = 15,5 ; 15,7Zone 3 (Mixed Zone) = 10:00:00:00:C9:20:DC:56 ; 15,12

Servers

Storage Array

FC Switch

Switch Domain ID = 15

Port 12


Lesson Summary


o FC SAN Topologieso Core-Edgeo Mesh

o Fabric management by zoning

Additional Task

Research on Fan-in & Fan-out

concepts


Chapter Summary

Key topics covered in this chapter:

o SAN features and benefits

o SAN connectivity options

o Port types and inter switch links

o FC protocol stack and addressing

o FC fabric topologies

o Fabric management by zoning


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Chapter 6

Technology

storage o

benefits o

o multimode o

components of san o

storage array o

component of san o

storage arrays o

devices o support