Transcript isd5.2_prnt

Storage Area Network
Chapter 6
ISMDR5.2:BEIT:VIII:Madhu N.PIIT
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Chapter Objective
Upon completion of this chapter, you will be
able to:
• Describe SAN and its benefits
• Discuss components of SAN
• Describe connectivity options of SAN
• Describe FC protocol stack and FC addressing
• List common FC topologies
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Lesson: Fibre Channel SAN
Upon completion of this lesson, you will be able
to:
• Define Storage Area Network and its benefits
• Define Fibre Channel
• List the component of SAN
• Describe three FC interconnectivity options
• List different FC port types
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Business Needs and Technology
Challenges
• Just-in-time information to business users
• Integration of information infrastructure with
business processes
• Flexible and resilient storage architecture
• DAS is inefficient to meet these challenges
– Storage Networking emerged as a solution
• FC SAN
• NAS
• IP SAN
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What is a SAN ?
Servers
• Dedicated high speed network of
servers and shared storage devices
• Provide block level data access
• Resource Consolidation
– Centralized storage and
management
FC SAN
• Scalability
– Theoretical limit: Appx. 15
million devices
• Secure Access
Storage Array
Storage Array
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Understanding Fibre Channel
• Fibre Channel is a high-speed network technology uses:
– Optical fiber cables (for front end connectivity)
– Serial copper cables (for back end connectivity)
• Latest FC implementations support 8Gb/s
 Servers are attached to 2 distinct networks
– Back-end
– Front-end
IP
network
Clients
Application
Servers
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FC SAN
Storage
Arrays
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FC SAN Evolution
Servers
Servers
Server
FC Switch
FC Switch
FC Switch
FC Hub
FC Switch
FC Hub
FC Switch
FC Switch
Storage Array
SAN Islands
FC Arbitrated Loop
Storage Arrays
Interconnected SANs
FC Switched Fabric
Fibre Channel SAN Evolution
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FC Switch
Storage Arrays
Enterprise SANs
FC Switched Fabric
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Components of SAN: Node ports
• Examples of nodes
– Hosts, storage and tape library
• Ports are available on:
– HBA in host
– Front-end adapters in storage
– Each port has transmit (Tx) link
and receive (Rx) link
• HBAs perform low-level interface
functions automatically to
minimize impact on host
performance
Node
Port 0
Port 0
Port 1
Port n
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Tx
Rx
Link
Components of SAN: Cabling
• SAN implementation uses:
– Copper cables for short distance
– Optical fiber cables for long
distance
• Two types of optical cables
– Single-mode
• Can carry single beams of light
• Distance up to 10 KM
– Multi-mode
• Can carry multiple beams of light
simultaneously
• Distance up to 500 meters
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Components of SAN: Cabling
(Connectors)
Node Connectors:
•
•
SC Duplex Connectors(1 Gb/sec)
LC Duplex Connectors(up to 4Gb/sec)
Patch panel Connectors
•
ST Simplex Connectors(used with
fibre channel patch panels)
Standard Connector
Lucent Connector
Straight Tip Connector
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Components of SAN: Interconnecting
devices
Basis for SAN communication
– Hubs(communication device in
FC-AL, share bandwidth, single
communication)
– Switches ( no sharing of
bandwidth , expensive, high
performance, use 24 bit
addressing to support 15 million
devices)and
– Directors(similar to switches, with
higher port count, and fault
tolerance capabilities)
HUB
Switch
Director
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Links, ports and topologies
• The Fibre Channel standard defines three different topologies:
fabric, arbitrated loop and point-to-point.
• Point-to-point defines a bi-directional connection between two
devices.
• Arbitrated loop defines a unidirectional ring in which only two
devices can ever exchange data with one another at any one time.
• Fabric defines a network in which several devices can exchange
data simultaneously at full bandwidth.
(There are three major Fibre Channel topologies, describing how a number of ports
are connected together. A port in Fibre Channel terminology is any entity that actively
communicates over the network, not necessarily a hardware port. This port is usually
implemented in a device such as disk storage, an HBA on a server or a Fibre Channel
switch)
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Fig 3.9 The fabric topology is the most flexible and scalable Fibre Channel topology
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Arbitrated loop
• The links of the arbitrated loop topology are unidirectional.
• Each output channel is connected to the input channel of the
next port until the circle is closed.
• The cabling of an arbitrated loop can be simplified with the
aid of a hub.
• End devices are bi-directionally connected to the hub; the
wiring within the hub ensures that the unidirectional data
flow within the arbitrated loop is maintained.
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• all topologies with devices like servers, storage
devices and switches must be equipped with
one or more Fibre Channel ports.
• In servers, the port is generally realized by
means of so-called host bus adapters (HBAs,
for example, PCI cards) that are also fitted in
the server.
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ports
• A port always consists of two channels, one input
and one output channel.
• The connection between two ports is called a
link.
• In the point-to-point topology and in the fabric
topology the links are always bi-directional.
• In this case( fabric topology) the input channel
and the output channel of the two ports involved
in the link are connected together by a cross, so
that every output channel is connected to an
input channel.
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Components of SAN: Storage array
• Provides storage consolidation
and centralization
• Features of an array
–
–
–
–
High Availability/Redundancy
Performance
Business Continuity
Multiple host connect
HBA
Arrays
HBA
FC SAN
HBA
Servers
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Components of SAN: SAN management
software
• A suite of tools used in a SAN to
manage the interface between
host and storage arrays
• Provides integrated management
of SAN environment
• Web based GUI or CLI
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SAN Interconnectivity Options: Point
to
Point
Point to point (Pt-to-Pt)
– Direct connection between devices
– Limited connectivity
Storage Array
Servers
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SAN Interconnectivity Options: FC-AL
• Fibre Channel Arbitrated Loop (FC-AL)
– Devices must arbitrate to gain control
– Devices are connected via hubs
– Supports up to 127 devices
FC Hub
Storage Array
Servers
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FC-AL Transmission
Node A
NL_Port
NL_Port #1
#1
HBA
Node D
Transmit
Hub_Pt
Hub_Pt
Byp
Byp
Receive
HBA
HBA
Byp
Byp
Receive
Transmit
Node B
NL_Port #4
NL_Port #4
HBA
Array Port
NL_Port
NL_Port #2
#2
HBA
Node C
Transmit
Receive
Receive
Byp
Byp
Byp
Byp
Hub_Pt
Hub_Pt
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NL_Port
#3
NL_Port #3
FA
HBA
Transmit
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SAN Interconnectivity Options: FC-SW
• Fabric connect (FC-SW)
– Dedicated bandwidth between devices
– Support up to 15 million devices
– Higher availability than hubs
Storage Array
Servers
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FC-SW Transmission
Node A
NL_Port
#1
N_Port #1
HBA
Node D
Transmit
Port
Port
Receive
Storage
Port
HBA
Receive
Transmit
Node B
NL_Port
#4
N_Port #4
HBA
N_Port #2
NL_Port
#2
HBA
Node C
Transmit
Receive
Receive
Transmit
HBA
Port
Port
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N_Port #3
Storage Port
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Port Types
Host
?NL-Port
?
NL-Port
Tape Library
Host
?NL-Port
Host
?
FC Hub
N-Port
F-Port
FC Switch
?
? ?
? ?
F-Port
FL-Port
E-Port
FC Switch
? ?
E-Port F-Port
N-Port
N-Port
Storage Array
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?
Storage Array
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Inter Switch Links (ISL)
• ISL connects two or more FC switches to each
other using E-Ports
• ISLs are used to transfer host-to-storage data
as well as the fabric management traffic from
one switch to another
• ISL is also one of the scaling mechanisms in
SAN connectivityMultimode Fiber
FC Switch
1Gb=500m 2Gb=300m
FC Switch
Single-mode Fiber
FC Switch
up to10 km
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FC Switch
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Login Types in a Switched Network
Extended Link Services that are defined in the standards:
• FLOGI - Fabric login
– Between N_Port to F_Port
• PLOGI - Port login
– Between N_Port to N_Port
– N_Port establishes a session with another N_Port
• PRLI - Process login
– Between N_Port to N_Port
– To share information about the upper layer protocol type
in use
– And recognizing device as the SCSI initiator, or target
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Lesson Summary
Key topics covered in this lesson:
• FC SAN and its components
• SAN Interconnectivity Options
• Port types and inter switch links
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Lesson: Fibre Channel Architecture
Upon completion of this lesson, you will be able
to:
• Describe layers of FC
• Describe FC protocol stack
• Discuss FC addressing
• Define WWN addressing
• Discuss structure and organization of FC Data
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FC Architecture Overview
• FC uses channel technology
• Provide high performance with low protocol overheads
• FCP is SCSI-3 over FC network
– Sustained transmission bandwidth over long distances
– Provides speeds up to 8 Gb/s (8 GFC)
• FCP has five layers:
–
–
–
–
FC-4
FC-2
FC-1
FC-0
Application
FC-4
SCSI
HIPPI
ESCON
ATM
FC-2
Framing/Flow Control
FC-1
Encode/Decode
*FC-3 is not yet implemented
FC-0
1 Gb/s
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2 Gb/s
4 Gb/s
IP
8 Gb/s
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Fibre Channel Protocol Stack
FC layer
FC-4
Function
FC-1
Mapping
interface
Common
services
Routing, flow
control
Encode/decode
FC-0
Physical layer
FC-3
FC-2
SAN relevant features specified by FC layer
Mapping upper layer protocol (e.g. SCSI-3
to FC transport
Not implemented
Frame structure, ports, FC addressing,
buffer credits
8b/10b encoding, bit and frame
synchronization
Media, cables, connector
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Fibre Channel Addressing
• FC Address is assigned during Fabric Login
– Used to communicate between nodes within SAN
– Similar in functionality to an IP address on NICs
• Address Format:
– 24 bit address, dynamically assigned
– Contents of the three bytes depend on the type of N-Port
– For an N_Port or a public NL_Port:
• switch maintains mapping of WWN to FC-Address via the Name Server
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World Wide Names
• Unique 64 bit identifier
• Static to the port
– Used to physically identify ports or nodes within SAN
– Similar to NIC’s MAC address
World Wide Name - Array
5
0
0
6
0
1
6
0
0
0
6
0
0
1
B
2
0101
0000
0000
0110
0000
0001
0110
0000
0000
0000
0110
0000
0000
0001
1011
0010
c
4
0
Company ID
24 bits
Port
Model Seed
32 bits
World Wide Name - HBA
1
0
0
Reserved
12 bits
0
0
0
0
0
c
9
Company ID
24 bits
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0
d
Company Specific
24 bits
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Structure and Organization of FC Data
• FC data is organized as:
– Exchange operations
• Enables two N_ports to identify
and manage a set of information
units
• Maps to sequence
– Sequence
• Contiguous set of frames sent from
one port to another
– Frames
• Fundamental unit of data transfer
• Each frame can contain up to 2112
bytes of payload
SOF
4 Bytes
Frame Header
24 Bytes
Data Field
0 - 2112 Bytes
CRC
4 Bytes
EOF
4 Bytes
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Lesson Summary
Key topics covered in this lesson:
• Fibre Channel Protocol Stack
• Fibre Channel Addressing
• Data Organization: Frame, Sequence and
Exchange
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Lesson: FC Topologies and
Management
Upon completion of this lesson, you will be able
to:
• Define FC fabric topologies
• Describe different types of zoning
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Fabric Topology: Core-Edge Fabric
•
Can be two or three tiers
Edge Tier
FC Switch
– Single Core Tier
– One or two Edge Tiers
•
•
FC Switch
FC Switch
In a two tier topology, storage
is usually connected to the
Core
Benefits
– High Availability
– Medium Scalability
– Medium to maximum
Connectivity
Server
Director
Core Tier
Single-core topology
Storage Array
Edge Tier
FC Switch
Core Tier
Director
FC Switch
FC Switch
Director
Server
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Dual-core topology
Storage Array
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Fabric Topology: Mesh
• Can be either partial or full mesh
• All switches are connected to each other
• Host and Storage can be located anywhere in
the fabric
• Host and Storage can be localized to a single
switch
FC Switches
Server
Partial Mesh
FC Switches
Server
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Storage Array
Full Mesh
Storage Array
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Fabric Management: Zoning
FC SAN
Array port
Servers
Storage Array
HBA
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Zoning Components
Zone sets
Zone set
(Library)
Zone
(Library)
Member
WWN's
Zone
Member
Zone
Member
Member
Member
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Zone
Member
Member
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Types of Zoning
Switch Domain ID = 15
Servers
Port 5
Port 7
Zone 2
Port 1
Storage Array
WWN 10:00:00:00:C9:20:DC:40
FC Switch
Zone 3
Port 9
Port 12
WWN 10:00:00:00:C9:20:DC:56
WWN 50:06:04:82:E8:91:2B:9E
Zone 1
WWN 10:00:00:00:C9:20:DC:82
Zone 1 (WWN Zone) = 10:00:00:00:C9:20:DC:82 ; 50:06:04:82:E8:91:2B:9E
Zone 2 (Port Zone) = 15,5 ; 15,7
Zone 3 (Mixed Zone) = 10:00:00:00:C9:20:DC:56 ; 15,12
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Lesson Summary
Key topics covered in this lesson:
• FC SAN Topologies
– Core-Edge
– Mesh
• Fabric management by zoning
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Concept in Practice – EMC Connectrix
• Connectrix family consist of
– Enterprise directors
– Departmental switches
– Multi-protocol routers
MDS-9513 Director
MP-7500B
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ED-48000B Director
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