Cisco --introduction-to-storage-area-networking-technologies

Introduction to Storage
Networking
Session CDC-101

Agenda
• Storage Basics and Terms
• Introduction to SANs
• SAN Connectivity—Fibre Channel
• SAN Applications
• SAN—Current Developments
• Cisco Storage Networking Partnerships

Storage Basics and Terms

Server
External
Storage
Clients
Server Attached Storage
• Server centric model—all storage
‘behind’ server CPU
• Data access is file system and
platform dependent
• Server CPU must handle not only
user I/O requests, but also:
User database inquiries
User file/print serving
Data integrity checking
Communication with
other devices
• LAN burdened with disk I/O traffic

I/O Channel
I/O Controller
External I/O Internal I/O
I/O Channel
• Simply stated, it is the technology which resides between
a computer and the device used to store its data
• This relationship can exist either internal to the
computer enclosure or can extend to external
storage devices
• Storage device is only accessible by attached host
computer
• Examples are SCSI, Fibre Channel, ESCON

Server NAS
File I/O
Network Attached Storage (NAS)
• Dedicated (thin) file server,
optimized for the specific
purpose of providing network
accessible storage to servers
over the LAN
• Attaches directly to network
• Capable of storage partitioning
• Uses network file system
protocols such as NFS or CIFS
• Suitable for applications
involving file serving/sharing

Redundant Array of
Inexpensive Disks (RAID)
• Fault-tolerant grouping of
disks that server views as
a single disk volume
• Combination of striping,
mirroring, and parity checking
• Self-contained, manageable
unit of storage
• Management: one file system
across entire virtual disk
• RAID delivers capacity,
performance, reliability,
and availability benefits

Just a Bunch of Disks (JBOD)
• Drives are independantly
attached to I/O channel
• Scalable, but requires
servers to manage
multiple volumes
• No protection in the
event of drive failure
• Drives share common
power supplies and
physical chassis

• Parallel interface I/O technology
• Maximum cable run length is 25 meters
• Speeds up to 320 MB/sec (Ultra SCSI-3 on 16-bit wide bus)
• Maximum of 16 (I/O controller + devices)
SCSI devices per bus
• Evolving standard: SCSI-1 SCSI-2 SCSI-3 SCSI-4
• Scalability and distance limitations rule out support of large
scale storage systems requiring disaster recovery
System With
SCSI Host
Adapter
Disk Tower
SCSI Index 1
Disk Tower
SCSI Index 2
SCSI Daisy
Chain Cable
SCSI
Terminator on
Chain Link Port
Small Computer System Interface (SCSI)

IBM S/390
Enterprise System CONnection (ESCON)
• Originally developed specifically for
use between IBM S/390 servers and
storage or other peripheral devices
• Standard widely supported in other
vendors storage products
• Transmits over fiber optic cable
• Max distance of 43 Km
• Max speed of 17 MB/sec
• Introduction of ESCON directors
(switches) allow dynamic connection
capabilities; original technology was
static point-to-point

Agenda

Introduction to SANS

LAN
(Packets)
SAN
(Blocks)
SAN Is a Dedicated Network for Attaching Servers to Storage DevicesSAN Is a Dedicated Network for Attaching Servers to Storage Devices
Clients
Heterogeneous
Servers
Storage Devices
Network
Interface
Card (NIC)
Host Bus
Adapter
(HBA)
SAN: What Is It?
LANLAN
SANSAN

• Gartner Group propose that a true SAN consists of a
“Connectivity” portion (device oriented) and a “Value”
portion (provides SAN services)
• “Connectivity” is provided by technologies such as
Fibre Channel devices, Escon, SCSI
• “Value” is delivered by software, functions like zoning,
masking, outboard backup, pooling, file sharing
SANSAN
ConnectivityConnectivity ValueValue
SAN Architectural Model
Gartner Group,1999
Gartner Group Symposium, Cannes, France, November 1999

SAN Components
• Servers with Host Bus
Adapters (HBAs)
• Storage systems
RAID
JBOD
Tape
Optical disk
• Hubs
• Switches
• SAN management
software

The Promises of SAN
• Massively extended scalability
• Greatly enhanced device
connectivity
• Storage consolidation/
centralized data management
• LAN-free, centralized backup
• Serverless (active-fabric) backup
• Server clustering
• Heterogeneous data sharing
• Disaster recovery—remote
mirroring

SANs: Scalability and Performance
• Storage expansion
No impact on servers
• Server expansion
No impact on storage
• Load balancing
Active parallel paths
• Bandwidth on demand
Robust topology

SANs: High Availability
• Multiple levels of redundancy are
configurable throughout data path (dual
HBAs, redundant fabric, server clusters)
• Multiple access paths allow failover cluster
configurations
• De-coupling of storage from applications
allows it to be managed independently
• Data vaulting and disaster recovery
configurations can address loss of
service due to site failures

SAN and NAS—Differences??
FCP, Serial SCSIFCP, Serial SCSI
Fibre ChannelFibre Channel
Server/DeviceServer/Device
Direct on NetworkDirect on Network
NoNo
NFS, CIFSNFS, CIFS
EthernetEthernet
Client/Server,
Server/Server
Client/Server,
Server/Server
Indirect via
NAS Server
Indirect via
NAS Server
YesYes
Protocol:
Network:
Source/Target:
Device Connection:
Embedded File System:
SANSAN NASNAS

SAN and NAS—When to Use What??
• NAS and SAN solutions solve different
application storage requirements
SAN is appropriate for DBMS (OLTP)
storage and most application scenarios
NAS is appropriate for file serving and
file sharing applications
…very few storage vendors or products
can meet all business needs
…very few storage vendors or products
can meet all business needs

Introduction to SANs—Summary
• SANs…
Fully exploit high-performance,
high connectivity network technologies
Expand easily to keep pace with fast
growing storage needs
Allow any server to access any data
Help centralize management of
storage resources
Reduce total cost of ownership

Agenda

SAN Connectivity—
Fibre Channel

What Is Fibre Channel?
• American National Standards Institute (ANSI)
standard drafted in 1988
• Combines the benefits of both channel and
network technologies
• SCSI and IP are the primary upper layer protocols
commercially available on Fibre Channel
• Benefits of mapping SCSI onto Fibre Channel
include:
Faster speed over parallel SCSI
Ability to connect more storage devices together
Greater distances allowed between storage devices
• Operates over copper (twisted pair) or glass
(fiber optic) cable

Fibre Channel Offers…
• Multiple protocol support
(today—mainly IP and SCSI)
• Networking (bridging and switching)
capability and functionality
• Heterogeneous interconnect
• Speed: 1 Gbps today, 2 Gbps in 2001 (ready
now on HBA’s); 10 Gbps in near future (2002)
• Boasts: bandwidth, availability, reliability,
integrity, and scalability

• Data block-based
• Closed—structured
• High performance
• Error free
• Large data transfer
• Hardware intensive
• Packet-based
• Open, unstructured
• Error-free secondary
• Peer to peer
• Data, voice, video
• Software intensive
Fibre Channel—Best of Both Worlds!
Fibre Channel—Best of Both Worlds
I/O Channel Network

Fibre Channel—Port Types
• ‘N’ port: Node ports used for connecting peripheral
storage devices to switch fabric or for point-to-point
configurations
• ‘F’ port: Fabric ports reside on switches and allow
connection of storage peripherals (‘N’ port devices)
• ‘L’ port: Loop ports are used in arbitrated loop
configurations to build storage peripheral networks
without FC switches; these ports often also have ‘N’ port
capabilities and are called ‘NL’ ports
• ‘E’ port: Expansion ports are essentially trunk ports used
to connect two Fibre Channel switches
• ‘G’ port: A generic port capable of operating as either an
‘E’ or ‘F’ port; if also capable of acting in an ‘L’ port
capacity—known as a ‘GL’ port

L
N
Fibre Channel Topologies
• Point-to-point
• Arbitrated loop
• Switched fabric
N
L
L
L
L L
N N
N N
F F
F F

N
N
Point-to-Point
• Dedicated connection between
‘N’ port Fibre Channel devices
• All link bandwidth
is dedicated to communication
between the two nodes
• Suitable for small scale
scenarios when storage
devices are dedicated to file
servers
N N

Fibre Channel Hub
Arbitrated Loop (FC-AL)
• TX of each node is connected
to the RX of the next node until
a closed loop is formed
• Maximum bandwidth:
100 MB/sec. (shared amongst
all nodes on loop)
• 126 nodes max on loop
• Not a token passing scheme—
no limit on how long a device
may retain control
• Operational sequence:
Arbitrate for control of loop
Open channel to target
Transfer data
Close
• Number of nodes on loop does
directly affect performance
L L
L L
LL
L L
FC

FC
FC
Switched Fabric
• Max nodes = 16 million
(24 bits)
• Max bandwidth = 100 MB/sec
• Nodes (N ports) connect to
fabric (F ports)
• End-to-end connection
managed by N ports
• Switching and addressing
handled by fabric
• E-Port provides trunk
connectivity to another
Fibre Channel switch
F
F
N N
F
N N
F
E
E

Loop 1 Loop 2
Node E
Node D
Node C
Node B
Node A
FC
Fibre Channel Switch
Combining Loops and Fabrics
• Fabrics can connect multiple arbitrated loops
• Each loop can only contain a single Fabric/Loop (FL) port
• Nodes on the loops can communicate publicly with other
devices reachable via fabric; alternatively, nodes can be
private, allowing them to only communicate with other
devices within their respective loop
F
N
NL
FLNL
NL
NLFL

Fibre Channel Zoning
• Zoning arranges FC connected devices into
logical groups
• Operation
Zone members can only see members in same zone
Zones are configured dynamically
Devices can belong to multiple zones
Zoning is supported on most Fibre Channel
fabric switches
• Benefits
Secured device access allows for operating system
co-existence

Node
A
Node
B
Node
C
Node
D
Node
E
Zone A
Fibre Channel Zoning Example
• Nodes A, B, and C can communicate with each other in zone A
• Nodes C, D, and E can communicate with each other in zone B
• Only node C can talk to all nodes on zones A and B
N N N
N
N
FC
Zone B

Fibre Channel Characteristics
• FC is divided into classes of service
Class 1: Dedicated connection; a virtual pipe
created between two N_Ports
Class 2: Multiplexed; each frame finds a route
to the destination, delivery or non-delivery is
acknowledged
Class 3: Datagram service; same as class 2
without acknowledgement

Fiber Channel—Specs
• Speed
Transfer rate: 1 Gbps (FC100)
Maximum user payload: 2112 bytes
• Distance
Copper: 100 M (@12.5 MB/sec)
Multimode fiber: 500 M (850 nm)
Singlemode fiber: 10 Km (1300nm)
• Connections
Point-to-point: 2 nodes
Arbitrated loop: 126 nodes
Switched fabric: 16 million nodes

16 Million 126 15
10 Km 10Km 25 M
100 MB/sec 100 MB/sec 160 MB/sec
Yes Yes No
Yes Yes No
160 MB/sec is maximum theoretical limit under specific conditions
Fibre Channel Fibre Channel SCSI
Fabric Arbitrated Loop Parallel
Connections:
Distance:
Bandwidth: *
Per Connection Shared Bandwidth Shared Bandwidth
Hot Plug Capable:
Multiple Protocols:
*
Fibre Channel—SCSI Comparison

Fibre Channel SAN Components
• Interfaces/Host Bus Adapters(HBAs)
• Hubs
• Switches
• Bridges and channel extenders
• Storage systems

Fibre Channel Host Bus
Adapters and Interfaces
• PCI to FC adapter
32/64 bit, 33/66 Mhz PCI 2.1
compliant
Other busses supported:
HSC, Sbus
100MB/sec FC performance
• Features
GBIC support (some vendors)
SNMP and MIB compliance
AL and Fabric login support
(vendor-specific)

Fibre Channel Hubs
• Typical port density
of 8 or 16 ports
• Supports arbitrated
loop topologies
• Configuration
management tools and
utilization monitoring
• Automated port isolation
(ring patching) and
device failover

Fibre Channel Hub Cascading
• Hubs can be cascaded
to increase the port
density of Fibre
Channel arbitrated
loops to allow up to
126 devices
• Logically—all devices
are on the same loop

Fibre Channel Hub Operation
• In example, node C suffers a failure and goes offline;
Fibre Channel hub senses failure and bridges break
in loop; remaining devices on loop remain connected
• Arbitrated loops built using Fibre Channel
hubs are self-healing
Node Failure
Hub Isolates
Fault
Node A Node CNode B
Fibre Channel Hub

Fibre Channel Switch
• Typically 8 to 64 ports—
some units larger
• Most support copper or
optical GBICs
• Support for port zoning
• Integrated SNMP and MIB
compliant management
• Automated port and
device failover
• Most offer N+1 hot
swappable components
for fault tolerance

Node A Node B Node C
Node D Node E
Fibre Channel Fabric Switch
Fibre Channel Switch Operation
• Node A has a fabric connection to node D
• Node B has a fabric connection to node E

Fibre Channel—SCSI Adapters
• Allows use of SCSI devices
on a Fibre Channel network
• Maps SCSI devices to units
of a single arbitrated loop
or fabric
• Allows use of Fibre Channels
by SCSI only hosts
• Typically available in multiport
configurations:
1 Fibre Channel—2 SCSI ports
2 Fibre Channel—4 SCSI ports

Fibre Channel—SCSI Adapters
• Adapter provides protocol translation between SCSI
and Fibre Channel
• Device controller provides either 7 or 15 SCSI device IDs
• Fibre Channel/SCSI adapter provides a virtual connection
from server node B to the SCSI storage system
SCSI
Fibre Channel/SCSI
Adapter
Fibre Channel
Arbitrated Loop
Fibre Channel
Arbitrated Loop
Node A
Node B
SCSI Storage
System
LL
LL
LL
Operation

Host
Initiator
Target
SANSAN
Fibre Channel Device Identification
• Used to map SCSI ID’s
to Fibre Channel
attached targets
• Three basic forms:
World Wide Node Name (WWNN)—
Assigned to Fibre Channel node
device by vendor
World Wide Port Name (WWPN)—
Assigned to Fibre Channel host
bus adapter port by vendor
Loop ID—Describes the loop ID
of a Fibre Channel loop identifier
assigned to ‘N’ ports via the network

Agenda

SANs Applications

SAN Applications
• High performance backup: multiple
servers using SAN to backup to a
shared backup resource
• Storage consolidation and expansion:
Consolidating storage for simplified management
Scaling storage to meet business needs
• Disaster protection
Clustering for fault tolerance
Remote real-time mirroring of data

The Backup Dilemma
• Problem
Increasing amounts of data to backup
Decreasing daily backup window
Increasing backup costs
• Solution
Centralized backup hardware
Reduced equipment and management costs
High bandwidth I/O channel to offload LAN
Improved backup performance
Scalable connectivity
Cost effective deployment

Network
Server
Network
Server
Backup
Server
Network
Server
Network Backup Today
LAN

Network
Server
Network
Server
(Backup
Node)
Network
Server
Network
Server
SAN
LAN-Free Backup
LAN

SAN
LAN
Serverless Backup
Network
Server
Network
Server
Network
Server

Storage Consolidation and Expansion
• SAN provides economies of scale in storage
allocation
Purchase driven by cost—not capacity
Allocation on demand—no waste
• SAN provides increased configuration flexibility
Multiple initiators
Multiple RAID levels
• SAN provides improved expansion capabilities
Add storage as required
Add I/O bandwidth as needed

Agenda

SANs—What’s Next??

Current Developments
in Storage Networking
• SCSI over IP (ISCSI)
Driven primarily by Cisco and IBM
• Fibre Channel over IP
Driven by CNT, Gadzoox, and Lucent
• Storage over IP (SoIP)
Driven by NiShan Systems
• Direct Access File System (DAFS)
Driven by Network Appliance

iSCSI—What Is It??
• ISCSI is the encapsulation of serial SCSI
protocol commands over IP frame
Parallel BusFCP
Fibre Channel
iSCSI
TCP
IP
SCSI Protocol

Offset Reserved Window
Well-known Ports:
21 FTP
22 Telnet
25 SMTP
80 http
5003 iSCSI
Source
Address
Destination
Address
Type IP TCP Data
46–1500 bytes
8 6 6 2
FCS
4 Octet
Preamble
TCP Header
Source Port
Sequence Number
Acknowledgement Number
Checksum Urgent Pointer
Options and Padding
iSCSI
Encapsulated
Opcode Opcode Specific Fields
Length of Data (after 40Byte Header)
LUN or Opcode-Specific Fields
Initiator Task Tag
Opcode Specific Fields
Data Field…
iSCSI Encapsulation
Destination Port
U A P R S F

iSCSI—How Is It Deployed?
• Utilizes best features
of SAN and NAS
• Leverages capabilities
of intelligent IP and
optical network
infrastructure
• Cost-effective
scalability for
e-business
Universal Access to Data and Storage
StorageStorage
NAS
IP
Network
Heterogeneous Clients
Heterogeneous
Servers
Tape
Storage
Appliances
Storage
Router
Storage
Router
Optical
MAN
Mainframe

iSCSI
• ISCSI is ubiquitous
• ISCSI is scalable
• ISCSI is manageable,
secure, and
interoperable
• ISCSI utilizes R&D
investment on
Ethernet/IP
Why Use iSCSI??

Problem: Fibre Channel
Homogeneous SAN Islands
• Fibre Channel SANs result in
vendor specific “SAN Islands”
• Islands can be a management
nightmare
• Inefficient universal access to
storage
• Limited device
interoperability
between islands
FC SAN
FC SAN
Vendor A
Vendor B
WAN

Why iSCSI??
Provides a Solution to Islands
• Solves the multi-vendor SAN
Island problem
• Best features of Fibre Channel
• Best features of IP networks
• Servers are utilized in
an optimal fashion
• Improves WAN
storage access
• Ease of management
Fibre Channel
SN 5420
F
C
Gbe
Integrated Multi-Vendor SAN
WAN

Why iSCSI?
Gain Universal Access to Storage
• Access storage from many
server operating systems
• Use existing security
infrastructure
• Use existing management
infrastructure
• Utilize network quality of
service and prioritization
features
SUNLINUX NT 4.0 WIN 2000
Fibre Channel
SN 5420
F
C
Gbe
IP
Network

Fibre Channel SANs
IP Networking
+
= IP—SAN
iSCSI: IP-SANs Enhance
Fibre Channel SANs
• Storage connectivity
• High-speed
storage access
• High availability
• Interoperability
• Scalability
• Familiarity
• Wide area access
• Security
• Management
• Quality of Service

iSCSI—Future Improvements
• IP latency and throughput
Bandwidth is not a bottleneck at gigabit
Ethernet speeds
• Overcoming CPU overhead
TCP will be implemented in server adapters
iSCSI will be implemented in hardware
Zero copy implementations
• Addressing security
Standard IP security functionality:
IPsec, 3DES, firewalls, ACLs, VLANs

Fibre Channel Over IP
• Simple encapsulation of Fibre Channel
blocks into IP packets
• Maps Fibre Channel fabric domains to IP
addresses
• IP Protocol 133 for Fibre Channel
encapsulated frames
• Will typically fragment blocks

FC SAN
FC SAN
Integrated Multi-Vendor SANIntegrated Multi-Vendor SAN
Why FCIP?
Integrates Fibre Channel Islands
• Fibre Channel over IP
allows integration of
multi-vendor Fibre
Channel SAN islands
over the IP WAN
backbone
• Accomplished by the
introduction of a new
network interface
element between the
Fibre Channel SAN and
the IP network
WAN

Agenda

Cisco Storage Networking
Partnerships

Cisco Storage Networking Partners

EMC Partnership
• ECOstructure—High availability
e-business initiative/blueprints
see url: http://www.eEcostructure.com
• DWDM certification—Metro 1500
• SRDF over IP solution (with CNT)
• EMC NAS solution
• Interoperability lab—EMEA UK
• see url:
http://www.emc.com/partnersalliances/
partner_pages/cisco.jsp

StandbyProduction
Symmetrix
EMC
Storage
Main Site
DWDM
Departmental Site
GE
FC FC
GE
FC Switch
Tape
NAS
Application/
Database
Servers
Metro
1500
Metro
1500
FCFC
Metro Applications with EMC:
FC SAN Extension
• Data center consolidation
• Fibre Channel e-port extension

StandbyProduction
Symmetrix
EMC
Storage
Production
DWDM
Metro
1500
Standby Data Center
SRDF/FC
SRDF/ESCON SRDF/ESCON
SRDF/FC
Metro
1500
Symmetrix
EMC
Storage
Connectrix
FC Switch
Connectrix
FC Switch
FCFC
Synchronous or
Asynchronous
Metro—Mirroring
• Synchronous mirroring—disaster recovery
(Raid-1 functionality)
• Asynchronous mirroring—backup, archiving, app testing
• SRDF over ESCON—direct connect
• SRDF over FC—via connectrix (Brocade) switch
• Requires EMC certification

StandbyProduction
Symmetrix
EMC
Storage
Production
EMC SRDFDWDM
Standby Data Center
SRDF/FC SRDF/FC
Storage
Connectrix
FC Switch
Storage
Remote DR
FC
New York New Jersey
London
Metro
1500
Metro
1500
Future
C6000
FC-PA
FCFC
FC
Synchronous/Asynchronous
Remote Mirroring
• Multi-hop
• Hybrid
sync/async
replication
Synchronous
FC-IP
IP
IP-FC
Asynchronous

Asynchronous
StandbyProduction
Symmetrix
EMC
Storage
Production
EMC SRDF
IP
Standby Data Center
SRDF/
ESCON
SRDF/
ESCON
Catalyst
6000
Symmetrix
EMC
Storage
SRDF/
IP
CNT Ultranet
Storage
Director
CNT Ultranet
Storage
Director
Catalyst
6000
SRDF
/IP
WAN Applications with EMC
SRDF Over IP
• Asynchronous mirroring—backup, archiving, app testing
• SRDF over ESCON to CNT Storage Director
• SRDF over IP—through Catalyst 6000 and across IP WAN
• Asynchrounous transfer only
• Requires EMC certification

IBM Partnership
• Cisco-IBM co-authored
iSCSI draft
• Metro 1500 DWDM
validation with IBM
Global Services (IGS)
• IGS certification of
SN5420 storage routing
product (in process)
• SAN/NAS partnership
expanding

Brocade Partnership
• BROCADE and Cisco multi-
phased development agreement
Internetworking of SANs over
IP-based MAN/WAN infrastructures
SAN to IP-based WAN
FC SAN connectivity in Cisco
catalyst 6000 first half 2001
SAN to IP-based optical MAN
BROCADE SilkWorm and Cisco
DWDM interoperability

Brocade Partnership Fibre
Channel Extension over IP
• Fibre Channel over IP via FC e-port
• TCP termination supports WAN
• Future FCIP catalyst 6000 blade
Standby
Storage
Production
Storage
Production
Application/
Database
IPFC Switch
Tape
C6500
Backup, DW, R&D
Customer Service
GE
FC
SCSI, FC,
ESCON
C6500
FC
FC
FC<>IP FC<>IP

Network Appliance Partnership
• Partnership to develop network-centric storage
solutions for enterprise customers
• Joint testing includes reference designs for
enterprise networks and storage mirroring
over IP WAN networks
• Products involved include network appliance
F700, F800, F85 filers and snap mirror software
as well as Cisco catalyst 4000 and 6500 switches

Server Farm
Distribution
Wiring Closet
Network Appliance F840 Filer Cluster
Clients
Catalyst
6500
Switch
Network Attached Data Center Model

PIX Firewall
Cisco
7200
Cisco
3640
Catalyst
Switch
Catalyst
6500
Switch
Network Appliance
F840 Filer Cluster
Network Appliance
F820 Filer
Remote Site
Central Site
Write
Acknowledge Snap Mirror
Server
Farm
Clients
Remote Storage over WAN Model
Internet

Additional Information
• Fibre Channel Industry Association (FCIA)
www.fibrechannel.com
• Storage Network Industry Association (SNIA)
www.snia.org
• Internet Engineering Task Force
www.ietf.org

Introduction to Storage
Networking
Session CDC-101

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