SAN Storage Area Network

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SAN (Storage Area Network)

• Laurent Prudhomme (1740307)
• Christopher Tremblay (1730728)
• March 02, 2002

"This report was prepared for Professor L.
Orozco-Barbosa in partial fulfillment of the
requirements for the course ELG/CEG 4183
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Overview
SAN (Storage Area Network)

• What is it? Example of usage
• Key Components
• SAN Interconnectors
• Data transfers
• FC and iFCP
• Benefits
• Future trends

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What is it?
SAN (Storage Area Network)

• A Storage Area Network is a dedicated, centrally
  managed, secure information infrastructure, which
  enables any-to-any interconnection of servers and
  storage systems.IBM

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Example of usage?
SAN (Storage Area Network)

• The government, having incredible loads of
  information (location of Bin Laden on satellite
  maps for example)
• Windows XP users actions recorded and stored by
  Microsoft Corp.

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Key Components
SAN (Storage Area Network)

• Clients
• Servers
• Interconnectors
• Storage Devices

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SAN Interconnectors
SAN (Storage Area Network)

• Cables (copper and fiber optic)
• Gigabit Interface converters (copper ?? fiber)
• Gigabit Link Model (generic fiber channel
  transceiver with intergrated key functions)
• Extenders (retransmits the signal)
• Multiplexers (conbining inputs into one stream)
• Hubs, Routers, Bridges, Gateways and Switches

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Network Topology
SAN (Storage Area Network)

• Point-to-point
• When only 2 nodes participate in an exchange
• Loop
• Every node is connected to their neighbor.
  (i.e.hub)
• Switched
• Routing the information to the requesting node.

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Data transfers
SAN (Storage Area Network)

• Storage-to-storage
• Common in systems when backups are needed.
• Server-to-server
• Useful for sharing processed data.
• Server-to-storage
• Connection allowing servers to treat raw data.

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FC-Layered Architecture
SAN (Storage Area Network)

• Fiber Channels is the transmission standard
  between computer devices.
• It supports IP, IPI, FCP and other such
  protocols.
• Implemented in layers based on the OSI 7 layer
  model (similar to TCP/IP).

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Layers (physical)
SAN (Storage Area Network)

• Layer 1 (FC-0)
• Responsible for the physical characteristics and
  the media. (ex cable)
• Layer 2 (FC-1)
• Defines how data is encoded and the transmission
  protocol.
• Layer 3 (FC-2)
• Determines the Class of service.

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Layers (upper)
SAN (Storage Area Network)

• Layer 4 (FC-3)
• Defines the service, which is known by all nodes.
  (ex striping definition)
• Layer 5 (FC-4)
• Specifies mapping of higher layers.
• Encapsulates protocols such as IP, FICON, FCP,
  etc.

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Class of Services
SAN (Storage Area Network)

• Dedicated Line
• A connection-based transmission which delivers
  frames with ACK in the same order as transmitted.
• Partially Dedicated
• A connection-based transmission which delivers
  frames with ACK in the same order as transmitted.
• Multiple Dedicated Line
• Similar to Dedicated Line, but with multicasting.

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Class of Services
SAN (Storage Area Network)

• Multiplexed Connectionless
• Multiplexes frames (with ACK) and doesnt
  guarantee the frame order.
• Unacknowledged Multiplexed Connectionless
• Multiplexes frames (without ACK) and doesnt
  guarantee the frame order.

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iFCP (Internet Fibre Channel Protocol)
SAN (Storage Area Network)

• Replaces the FC-2 with an IP network.
• It provides a serial SCSI interface to the OS.
• Allows the FC to be addressed as standard SCSI to
  the OS.
• Addresses from domains are mapped onto others
  through the Gateway architecture.
• Frames from the IP domain are mapped to Fibre
  Channel port_ID addresses which are passed to the
  upper layers used by FC devices.

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iFCP (Internet Fibre Channel Protocol)
SAN (Storage Area Network)
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iFCP outbound mapping
SAN (Storage Area Network)
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iFCP inbound mapping
SAN (Storage Area Network)
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iFCP header
SAN (Storage Area Network)
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iFCP vs FCP
SAN (Storage Area Network)
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Benefits of SANs
SAN (Storage Area Network)

• Data Availability
• Data is separated from the application.
• Centralized Data
• Makes it scalable and the flexible.
• Backup
• Serverless backup process.
• Offload
• Application has more processing power.
• Management
• Provides a single window into the storage entity.

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Future
SAN (Storage Area Network)

• Tests are currently underway for bring the fiber
  channels data rate up to 200 and 400 Mb/sec
  (compared to the 100 Mb/sec of today)

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Possible QuestionsAll the answers are contained
in one slide of this presentation
SAN (Storage Area Network)

• What is SAN and what does it mean?
• What are the benefits of using a SAN?
• Give example situations where SAN could be useful
• What kind of data transfer is there?
• How is a SAN device diffrent from a non-SAN
  device
• SAN stands for Secure Area Network T/F
• What topologies can be used with a SAN

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Reference
SAN (Storage Area Network)

• IBM ( redbook)
• http//www.storage.ibm.com/ibmsan/
• NetworkComputing
• http//www.storage.ibm.com/ibmsan/san_basics.htm