Storage Area Networks and Fibre Channel

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Storage Area Networks and Fibre Channel

• Steven Wilson
• Preetham Gopalaswamy
• Brocade Communications Systems, Inc.

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Todays Topics

• Storage Area Networks
• Fibre Channel Technology
• Fibre Channel Management
• Common Information Model (CIM)

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The Server-to-Storage Bottleneck
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1990s Technology Does Not Scale
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What is a SAN?

• Open Systems Model for Network Storage
• Enhanced Storage Management
• Flexibility to add or reconfigure storage as
  needed without downtime
• Independent Scaling of CPU and Storage capacity
• De-couples servers and storage so that either can
  be scaled separately
• Easy Migration
• Current applications run without software changes
• Incremental deployment allows flexible adoption

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SAN Benefits

• Dynamic Allocation of Resources (storage and
  applications)
• High Data/Application Availability
• Non-disruptive Maintenance
• Continuous operations if server or storage has to
  be removed from cluster
• Add, delete storage on the fly
• Cost Savings
• Shared Storage

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What is Fibre Channel

• Open standard, ratified in 1993
• Optimized for large block transfer with built-in
  reliability
• Distance¾for disaster tolerant configurations
• Independent scaling of servers and
  storage¾creating the virtual private data
  center/Virtual Private SANs
• Adopts legacy environments and applications
• Concurrency of networking and storage protocols
  on single NIC¾reducing costs of ownership SCSI,
  IP, VI, FICON, Etc.
• Single technology for server-storage area
  networking, clustering (server-server)

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Fibre Channel Standards Activities
T11

• Fibre Channel transport,Topology, Generic
  Services, physical, media standards

SNIA

• SAN Application,discovery,security, management
  Standards. Not yet an accredited standards body,
  but provides input to other standards bodies

IETF

• IP related standards and MIBs and Storage over IP
  efforts

T10

• SCSI storage protocols for Fibre Channel and
  others

DMTF

• Fibre Channel work group, Common Information
  Model (CIM)

FCIA

• Fibre Channel technology road maps,
  interoperability specifications and plug-fests

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Important T11 Standards

• FC-FS Framing and Signaling, Replaces FC-PH,
  FC-PH-2, and FC-PH-3
• FC-SW-2 and FC-SW-3 Switch Fabric Standard,
  Describes How Switches Communicate with One
  Another
• FC-GS-3 and FC-GS-4 Generic Services, Describes
  the Well-Known Server Architecture and Related
  Transports
• FC-BB-2 Backbone, Describes How Fibre Channel
  Frames are Transported Over WAN Connections
• FC-MI Methodologies for Interconnects,
  Interoperability Profile, FC HBA API
• FC-SP Security Protocols, Authentication,
  Authorization, Policy Management, Confidentiality

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Fibre Channel- Hybrid Transport System -
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Multiple Protocols On Common Fibre Channel
Transport
Multiple Mapping Standards
Streams Transfer
FICON
CT
Single Transport Standard
10 GB
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FC-0

• Physical Variants
• Optical (Laser, LED)
• Copper (Coax, Twisted Pair)
• Single Mode vs Multi-mode Fibre

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FC-1

• 8B10B Encoding
• Running Disparity
• Ensures Virtually An Equal Number of 1s and 0s
• DC-Balanced
• Facilitates Amplifier Design Lower Power
• Ensures Synchronization For Clocking Purposes
• IBM Holds the Patent

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Fibre Channel Information Transfer FC-2
Layer¾Framing and Protocol
Sequence 3
Sequence 2
Packets (Large Blocks)
Exchange (Protocol Operation)
Sequence 1
Sequence
FC Frame (Max. 2112 Bytes)
Device 2
(server/storage/WS)
Device 1
(server/storage/WS)
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FC-4 Mappings

• Maps Upper Level Protocols to Fibre Channel
• Examples are SCSI, IP, VI, FICON
• FC-CT is Mapped for Inband Management Use

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Fibre Channel Ports and Nodes

• N_Port, NL_Port, F_Port, FL_Port, E_Port, B_Port
• Each Nx_Port Has a Fabric Unique 24 Bit Address
• Each Nx_Port Has a Unique WWN
• Nx_Ports Must Login With One Another Prior to
  Data Transfer
• When a Fabric Exists, Ports Also Login to the
  Fabric
• A Node is a Collection of Ports
• Each Node Has a Unique WWN

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Data Transport Services- Meet Different
Application Needs -
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Fibre Channel Topologies

• Point-to-point¾two devices connected together

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Fibre Channel Topologies

• Arbitrated loop
• Up to 126 devices on a shared media for small
  systems at reduced cost and reduced performance
  level

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Fibre Channel Topologies¾the Fabric

• Large connectivity on non-shared media, which
  allows concurrent communicating pairs
• Highest performance level
• High scalability
• Good fault isolation
• Embedded management and services

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Fibre Channel Services

• Login Server
• Fabric Controller
• Common Transport
• Name Server
• Alias Server
• Time Server
• Management Server

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Port Interfaces
NL_Port
F_Port
N_Port
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Point-to-Point Remote Connection between Fibre
Channel Systems Through WAN
Fibre Channel switch
Fibre Channel switch
ATM/ SONET/IP network
Fibre Channel switch
FC-BB-2 and FCIP Standards
Fibre Channel switch

• Remote Backup
• Remote Mirroring
• Disaster Recovery

WTU Wan Tunneling Unit
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Characteristics of FC Switches

• Switches Connect to One Another Using E_Ports and
  Inter Switch Links (ISLs)
• Switches Route Frames Based on the 24 Bit DID
• DID Consists of 8 Bit Domain ID, 8 Bit Area ID,
  and 8 Bit Port ID
• Each Switch Has a Unique Domain ID (239 Max)
• Switch to Switch Communication Uses Class F Which
  is Similar to Class 2
• Switches Implement a Fabric Controller and other
  Well-Known Servers
• Switches Allow Inband and Out-Band Management

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Functions of the Fabric

• Switch Port Initialization
• Fabric Configuration
• FSPF
• Zoning
• Distributed Server
• RSCN

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Zoning

• Similar To VLANs in the Networking World
• Provides an Access Control Mechanism
• Allows End-Devices to Only Communicate With
  End-Devices in the Same Zone
• Two Types of Enforcement
• Hard
• Soft
• Affects the Discovery Process
• May Eventually be Applied to Resources Behind the
  N_Port (e.g. LUNs)

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Zoning Structure
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Fibre Channel Generic Services

• Registry and directory service to discover nodes
  and their attributes (connected to Fabric)
• Integrated with Fabric and
• Distributed
• Operational in Nature

• Registration and discovery of Switches, Fabric
  ports and their attributes.
• Configuration Management
• Fabric Device Management
• Zone Management
• Integrated with Fabric and
• distributed

• Discovery of Physical topology
• Discovery of Logical association between devices
• Acquires topology information from Simple Name
  Service and Management service

N_Port
FC-GS-3 FC-GS-4 Standards
Fibre Channel Fabric (Distributed Services)
N_Port
N_Port
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Brocade Software Stack
S A M S
Kernel Drivers
Platform Group
OS Kernel
Hardware
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Traditional Fibre Channel Management

• Common Transport (FC-CT)
• Standardized Native Inband Management
• IP over FC
• Proprietary In-band Management
• WEB Based Management
• Out of Band Proprietary Management
• SNMP
• Standardized (Almost) Out of Band Management
• Telnet/CLI
• Proprietary Out of Band Management
• API Based Management
• Proprietary Management Out of Band Management

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Post Modern Fibre Channel Management

• Object Based Management
• CIM/WBEM (Web-based Enterprise Management)
• Combines Management Capabilities Exposed Through
  Other Interfaces
• CIM Capabilities Can be Provided By Agents or
  Integrated Directly Into SAN Products

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Managing Brocade Fabrics
API
SNMP
WebTools
Fabric Manager
Management Agent
Brocade Data Model
Fabric
RPCd
SNMPd
HTTPd
Switch Unified Data Access Layer
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CIM Common Information Model

• It is a Data Model, not an implementation
• There are two parts to CIM
• The CIM Specification
• CIM Schema
• CIM Specification (currently 2.2) describes the
  language, naming, Meta Schema (a formal
  definition of the model)
• Formal definition of the CIM Schema is expressed
  in a Managed Object File (MOF)

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Everything about CIMthat you really did not want
to ask
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Everything about CIMthat you really did not want
to ask

• Objects have inheritance
• Abstract and Concrete
• Objects have methods Intrinsic and Extrinsic
• Objects can maintain backward compatibility and
  support deprecation
• Associations are objects which means they can
  have properties
• Events are Objects
• CIM Schema provides the actual model descriptions
• Core Schema
• Common Schema (System, Network, Devices,)
• Extension Schema
• CIM 2.7 has simplified the Fibre Channel model
  and added Zoning

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Everything about CIMthat you really did not want
to ask

• The methods supported by a class vary with what
  interfaces/interface methods a given provider
  supports for that class.
• Instance Provider
• deleteInstance
• createInstance
• getInstance
• setInstance
• enumerateInstanceNames
• enumerateInstances
• PropertyProvider
• setProperty
• getProperty
• Method Provider
• invokeMethod
• Query Provider
• invokeQuery

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CIM-based Management Solution
Access Protocol and Data Format
Data Information Model
Customer Deliverables
Agent
Client I/F
Object Manager
Higher Level Services
Provider I/F
Device Provider
Fabric Data Access
Fabric Layer
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Peeking under the hood
To Provider
Host
Fabric
RPC Daemon
Http Daemon
SNMP Agent
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Why move to a CIM-agent solution?

• Looser linkage between application and Brocade
  library
• Less integration headaches
• More flexible application interfaces (i.e. java
  and other compilation environments)
• Agent can support multiple applications
  simultaneously
• Delivers a standards-compatible interface (e.g.
  CIM)

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Questions
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Thank You!