storage basic concept

8/3/2019 Storage Basic Concept

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Agenda

Basic Concept of Storage Hard Disk Drive Technology

RAID Controllers and Levels

Fabric Technology

FC Topologies

Nodes and Ports

Storage Infrastructure Components

Classes of Services Fabric Protocols

Thank you


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Hard Disk

Invented : September 13, 1956 Invented by : Reynold Johnson

Connects to: Motherboard via one of

PATA, SATA, SCSI, SAS, FC

External enclosure via one of

USB 1.1/ 2 , FireWire 400/ 800

Interface: IDE, USB, SCSI, FC

Seagate, IBM, Maxtor,

Capacity: 20- 180 GB

Data Transfer Rate: over 100MB/s
http://en.wikipedia.org/wiki/September_13http://en.wikipedia.org/wiki/1956http://en.wikipedia.org/wiki/Reynold_Johnsonhttp://en.wikipedia.org/wiki/USBhttp://en.wikipedia.org/wiki/FireWirehttp://en.wikipedia.org/wiki/Image:IBM_old_hdd_corrected.jpghttp://en.wikipedia.org/wiki/FireWirehttp://en.wikipedia.org/wiki/FireWirehttp://en.wikipedia.org/wiki/USBhttp://en.wikipedia.org/wiki/USBhttp://en.wikipedia.org/wiki/Reynold_Johnsonhttp://en.wikipedia.org/wiki/Reynold_Johnsonhttp://en.wikipedia.org/wiki/Reynold_Johnsonhttp://en.wikipedia.org/wiki/1956http://en.wikipedia.org/wiki/September_13


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Disk Drives BasicsPlatter

A round magnetic plate that is used to write data to and readdata from.

SeekMoving the heads from one track to another, oftenmeasured in time.


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Disk Performance

There are 5 primary factors that affect the

overall performance of a disc drive.

Rotation speed

Speed of the I/O Technology implemented

Seek time

Latency

Speed and size of the disc drive buffermemory

Data Transfer Time


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5

Disc Drive Interfaces

Interface Typical Applications

ATA (IDE) Notebooks, desktop PCs, andworkstations(Parallel IDE/ATA)

SATA Now replacing ATA/IDE in notebooks &Workstations. Also being used in someEnterprise arrays, JBODs and backup

systems(Serial ATA (SATA))Parallel SCSI Servers, high-end workstations, and early

RAID

Serial SCSI Servers, workstations, and Enterprisearrays(Serial Attached SCSI (SAS)

FC-AL High-end Enterprise arrays and JBOD

IBM SSA High-end proprietary IBM Systems


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Hard Disk Controller

A device that controls the transfer of data from acomputer to a peripheral device and vice versa.

ATA Controller, SATA Controller

SCSI Controller, FC Controller, SAS Controller

eSATA Controller

RAID Controller

A RAID controller is a device which managesthe physical storage units in a RAID system andpresents them to the computer as logical units.

Software RAID

Hardware RAID


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RAID Levels

RAID 0 Data striping without parity

RAID 1 Disk mirroring (Mirrored Volumes)

RAID 2 Bit Level Striping with Dedicated Parity

RAID 3 Byte Level Striping with Dedicated Parity

RAID 4 (Block Level) Concurrent access, dedicatedparity drive

RAID 5 Concurrent access, distributed

parity

RAID 6 Double striped to support 2 drive failures

RAID 1+0 Disk mirroring and data striping

without parity

RAID 0 + 1Stripe of Mirrors

7 10

Redundant Array of Independent Disks


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The selection of the internal physical hard disks;

The I/O technique used for the communication within the disksubsystem;

The use of several I/O channels;

The realization of the RAID controller;

The size of the cache; and

The cache algorithms themselves.

RAID level Fault-tolerance Readperformance Writeperformance Spacerequirement

RAID 0 none good very good minimalRAID 1 high poor poor highRAID 10 very high very good good highRAID01 High poor poor minimalRAID 4 high good very very

poorlow

RAID 5 high good poor low


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What is a Fabric

Switch or group ofconnected switches

Routes traffic betweenattached devices

Domain ID Unique switch identifier

Switch Services

Login Service assigns ID to

nodes at login Name Service stores node

information

Host

SWITCH

LoginService

NameService

Fabric

ArrayDisk

Application

O/S

File System


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What is Fibre Channel ?


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FC Topology

NodeNode

Node

Node

NodeNode

Node

Node

Node

Node

Node

Node

Node

Node

Node

Node Node

Switched Fabric

Arbitrated Loop

Point-to-Point

N t St I f t t C t


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Storage Net Storage Infrastructure Components gComponents

Cables and connectors Gigabit Link Model (GLM)

Gigabit Interface Converters (GBIC) Adapters Hubs Routers

Bridges Gateways Switches Directors


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Storage Networking Components HBA A Host Bus Adapter is a card that connects data peripherals and

server host buses like PCI. A software device driver for each

model of HBA is required by the operating system. Types: FC and GigE

QLogic, Emulex, McData

HBA


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Common File Systems

UNIX (UFS) Stable, familiar, available on multiple platforms

VERITAS (VxFS)

Modern, optimized for SAN, multiple platforms

SGI (XFS)

Scalable for very large file systems and files Windows NT (NTFS5)

Large installed base, familiar, supports dynamic reconfigurationand fault recovery

NFS and CIFS

UNIX file system designed for networked file sharing DAFS

New NAS/SAN file system designed for data sharing


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A World Wide Name, or WWN, is a 64-bit address used in fibre channelnetworks to uniquely identify each element in a Fibre Channel network.

Afixed 64-bit World Wide Node name assigned by the manufacturer.

A Node is a fibre channel device

A port is a Fibre Channel access point

A link is a unidirectional media pair

Port 0

Port 1

Node

Port 0

Transmitter

Receiver

Node

Transmiter

WWN, Nodes, Ports


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Fibre Channel Terminology

Node Port

N_Port N_Port

Node Node

Fabric Switch

Fabric Port Extension Port

F_Port F_Port

E_Port

E_Port


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Fibre Channel fits in the lower three layers(approximately) of the OSI model:

Physical

Data link

Network

Other protocols, likeSCSI, are responsiblefor the upper layers

Fibre Channel Layered Model

Ethernet

Application

Presentation

Session

Transport

Network

Data link

Physical

IP IPX ...

TCP SPX ...

HTTP FTP

SNMP ...CIFS

NFS DAFS ...

OSI Layers

Fibre Channel

SCSI IP

HiPPI ...


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Optical cables

Electrical cables

Media Characteristics

Speed: 1, 2, 4, or 10 Gb/s

Distance:

Multimode up to 500m

Single-mode up to 10Km

Up to 120Km with CWDM GBICS

Speed: 1, 2, or 4 Gb/s Distance: up to 33mHSSDC

Multimode optical,SC connector


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Fibre Optic Technology

Single mode fiber(9 core)

Jacket

Fiber

coating

Fiber

cladding

Optical core

Kevlar buffer

2.5mm

Multimode fiber(50, or 62.5 core)


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Optical Connectors(1GB)

The SC connector is typically used for 1Gb optical cabling:

Follow-on to the ST connector Both simplex and duplex (0.5 centerline) connectors are supported

Duplex SC

ST

SC Optical GBICTransceiver


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2Gb/4Gb Optical Connectors

Lucent Connector (LC):

Generally used with SFPs for 2Gb links

About half the size of SC duplexconnectors

Provide greater density

LCLC Optical SFP Transceiver

LC Optical SFFBoard-Mount Transceiver


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Transceivers(GBICs)

GigabitInterface Converters Hot-pluggable transceivers

Form factor pioneered by Compaq, SUN, and Vixel

Typically use a 20-position, SCA-2

copperconnector (SC)

Provide media and connector conversion


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SFPs/SFFs

Small Form-factor Pluggable/Fixed

Used with 2Gb components

Same architecture as GBICs

Allow higher port density SFF is same form factor, but fixed and not pluggable

SFP


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Classes of Service

Class 1

Class 2

Class 3

Class 4

Class 6

Connection-oriented

Confirmed delivery

Frame-switched

Confirmed delivery

Frame-switched

No delivery confirmation

Fractional bandwidth virtual

circuit

Confirmed delivery

Multicast, connection-oriented

Confirmed delivery

Specialized

applications; not widely

used

Clustering, OLTP

Controlled

environments;

streaming audio/video

Specialized


supported

Specialized


Characteristics Use

Multiple classes of service can co-exist within a fabric.

Fibre Channel Addressing


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Fibre Channel Addressing

Point to point:

Simple: 000000 or 000001

FC-AL:

Arbitrated Loop Physical Address (AL_PA)

8 bits = 127 addresses per loop

126 for nodes + 1 for FL_Port

Switched fabric:

Fibre Channel Port ID (FCID)

24 bits = 16 million potential addresses perfabric


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World-Wide Node Name (WWNN):

Uniquely identifies entire device (node) or

May be unique per Port on each nodal device.

World-Wide Port Name (WWPN):

Uniquely identifies each port in that device

Used to facilitate services such as routing andzoning

21 0000203701EF25

22 0000203701EF25

20 0000203701EF25WWNN

WWPN A

WWPN B

Example: Seagate Disk Drive

WWNNs and WWPNs

M lti thi


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Multipathing Multipathing drivers provide three basic features:

Failover:

Detection of link failure

Automatic rerouting to alternate path

Varying levels of transparency

Load-balancing: Path selectionper-LUN

Dynamic traffic leveling

Administration:

Intelligent path selection

Dynamic configuration

Centralized configuration

Login Server


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Login Server

Responsible for assigning port addresses for alldevices on the fabric

Ports send a login frame (FLOGI) to this serverwhen they come online

Login Server responds by assigning a port

address (FC_ID) Fabric Login

Port Login

Process Login Fabric Protocols


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IP Storage Comparison

Tunnels FCframes over IP

networks (singlename space)

Transports FCframes over IP

networks (NATand proxy)

Transports serialSCSI-3 via TCP/IP

SAN-to-SAN SAN-to-SAN anddevice-to-device

Device-to-device

SAN extension SAN extension Host-to-targetconnectivity

Protocolarchitecture

Networkarchitecture

Primaryapplication

iSCSIiFCPFCIP

Expanding Fabric Connectivity


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Expanding Fabric Connectivity

Interswitch Links - ISL

Switch to switch communication

Transfer Host to Storagedata

Transfers fabricmanagement traffic

Number of Links

Redundancy Bandwidth requirements

Use ControlCenter, WLA,Connectrix Manager

Refer to Support Matrix

recommendations Distance

Long-wave laser opticsusing singlemode FiberOptic cables

Short-wave laser opticsusing multimode cables

ISL


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What are those numbers ?

Exabyte

Terabyte

Gigabyte

1,208,925,819,614,629,174,706,176

1,073,741,824

280

250

230

240

"Given good conditions(!), downloading a 1 yottabyte file over a 28.8Kbps connection would take about 140 billion years."

1,099,511,627,776

1,048,576 220 Megabyte

1,125,899,906,842,624 Petabyte

2601,152,921,504,606,846,976

270 Zettabyte

Yottabyte

1,180,591,620,717,411,303,424


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THANK YOU

storage basic concept

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