Storage Networking Strategic Decision-Making

Randy KernsEvaluator Group, Inc.www.evaluatorgroup.com

Agenda

Recap – What you’ve heard• Storage Networking

• Definition, what problem is being solved

• Differing Solutions• SAN – FC, IP (iSCSI, iFCP, FCIP)• NAS

Framework For Decision-Making• Evaluation

• Requirements based on market segment• Where proposed solutions best fit• Considerations for your environment

• Roadmap for choosing storage networking solution• Methodology to approach problem

Storage Networking

Definition – from SNIA• The practice of creating, installing, administering, or

using networks whose primary purpose is the

transfer of data between computer systems and

storage elements and among storage elements.

What problems are being solved• Near-term: consolidation, backup

• Wider-view: storage growth

Different Solutions

Storage Area Networks• Fibre channel based

• Fabric switched network for SANs– High bandwidth – 1, 2 Gb/s now, 10 Gb/s mid 2002– Low latency – hardware intensive implementation– Block I/O – SCSI as ULP for fibre channel

• Interoperability – Solved with significant investment from vendors– Independent lab and certification underway– Maturing – significant deployment

• Major vendors – Products– Commitment for long term

• Management and the abstraction of storage

Different Solutions

Storage Area Networks• IP based

• Over Ethernet with TCPIP encapsulation for most

• Various methods – proposals for standards

– Block I/O via encapsulation

» iSCSI

– Tunneling

» iFCP

» FCIP

• Targeting OLTP at higher transaction rate than

NAS

Different Solutions

Storage Area Networks• IP based – iSCSI - uses SCSI commands over IP

• Target is to provide block I/O using Ethernet infrastructure

• No mechanism in Ethernet/IP to allow for command-response structure of SCSI• SCSI is block oriented storage interface• Uses a software driver to control SCSI protocol

• Ethernet / IP has network characteristics• No flow control – drops packets on congestion• Packet size is limited – get smaller as contention increases• iSCSI attempts to work within these constraints

• iSCSI standard proposes to encapsulate SCSI on TCP

• Many vendors – some haven’t been in storage before

Different Solutions

Storage Area Networks• IP based – iFCP, internet Fibre Channel Protocol

• Transfers FCP across IP networks• Gateways used to encapsulate FCP on IP• Useful for extended distances for FC connections• Translates FC frame addresses to new local IP address

– ‘Transparent’ view of storage devices– Connects FC devices to TCP/IP backbone

• IP based – FCIP, Fibre Channel Internet Protocol• Tunneling FCP across IP• Gateways/switches act as E-port extenders• Useful for SAN to SAN linkage over extended distances• Does not change FC address of frames between SANs

– Makes a large SAN with single address space

Different Solutions

Storage Area Networks• InfiniBand

• Developing technology to replace PCI in servers

• Will extend from server to fabric

– Connect storage, networks, etc.

– Switch / routers will be initial connect

• Question is: when will native InfiniBand devices

appear?

• Infrastructure change – will happen

– Probably 5 years to reach into storage

Different SolutionsNetwork Attached

Storage• NAS Appliances

• Remote file serving

• Clustering option

• Starting to see

abstraction within

same vendor

solutions

Application

Rem oteFile System

DiskSystem

Netw ork Attached Storage

Com puterSystem

Local Area Netw ork

FileRedirector

NAS Device

Different Solutions

Network Attached

Storage• DAFS

• VI based

• Remote DMA

• File-based access

• Targeting OLTP at higher

transaction rate than NAS

• YE2001 availability

VIPL API

File Access API

Buffers

Application

DAFS

VIPL

VI NICDriver

VI NIC

User

Kernel

Hardware

Data

Control

Different Solutions

Convergence –

blurring of the

lines• Gateway – NAS “head”

• Connect to SAN

storage

• Benefits of scaling

storage,

administration

D isk a rray

LAN

NetworkAttachedStorageServer

SAN Fibre C hannelL ink

for storage,backup/restore

Different Solutions

Convergence –

blurring of the

lines• Metadata server

solutions

• NAS control for

access

• SAN block I/O for

data

to achieve high

performanceMetadata Server

Servers

SAN

Disk array

File Request

Location Information

Block I/O

Disk array

LAN

Different Solutions

Convergence –

blurring of the

lines• Distributed SAN file

systems

• SAN data can be

local file system

Cluster Vol Cluster Vol

Host B Host C

Cluster Vol

Host A

SAN

ClusterFile System

ClusterFile System

ClusterFile System

Cluster Sfw Cluster Sfw Cluster Sfw

Single File System Common file system on shared storage Highly available

Application transparent

Framework for Decision making

Evaluation• Understand your requirements

• Business

• Technical

• Understand the vendor offerings

• Targeted at a specific market segment

• Characteristics may not fit your requirements

• Need to have long-term view

Markets

NAS

SAN

NAS

SAN

Enterprise

Departm ental

SAN

W ork Group

SAN

NAS

NAS

Traditional IT New e-Business

Storage Service Providers

Professional Services

Today's Bifurcated Storage MarketProliferation of SAN and NAS

Entry

M id

Large

Requirements by Segment

Enterprise DataCenter• Reliability – 100% availability of data

• Guaranteed performance – response time, data rate

• Scalability – capacity and performance

• Security – guaranteed and provable

• Long-term support from vendor

• Tools for storage and performance management

• Integration into mature procedural environment

Requirements by SegmentDepartmental (Small Business) /

Workgroup• Cost

• Simple administration

• Quick ROI

• Multi vendor: server, OS, storage systems

New E-business• Cost

• Simple administration

• Potential large capacity

• Availability by replication

• Mature into traditional IT environment

Where Does Solution Best Fit

Enterprise DataCenter• FC-based SANs

• High performance, highly scalable

• Designed for storage – fits requirements for

enterprise storage

• Security implementation / control familiar to

storage professionals

• Significant deployment in enterprise

(Fortune 1000 companies)

• NAS

• Appliances in mainly R/O environments

• Metadata server in file sharing / performance

environments

Where Does Solution Best Fit

Departmental (Small Business) /

Workgroup• IP based SANs

• May be least cost

• Few storage-only professionals (normally system

administrators with multiple responsibilities)

• Perception of simplicity

• NAS

• Appliances

• SAN file systems

• Gateway

• FC based SANs

• Complete solutions without major installation effort

Where Does Solution Best Fit

New E-business• In SSP and professional service installed / managed

environments: FC based SANs

• IP-based SANs for existing and growth environments

• NAS

• Appliances

• Gateway

• All of the above

Other Considerations

Considerations for your environment• Will there be multiple storage networks?

• Independent?

• Distance

• What information needs to flow?

• What are the bandwidth, response time

requirements?

• Plan for the future

• Growth

• Additional requirements

– Security

– applications

Storage Network LinkageEnterprise to Enterprise

• Data migration over extended distances

• Performance requirements and distance dictate

connection

• Transfer over IP

– Multiple solutions

• ATM, other tunneling solutions

• Business continuance

• Remote copy – critical performance characteristic

drive connection topology

• SAN may be utilized by storage system to storage

system copy (example PPRC)

• System-level issue not just data movement

Storage Network LinkageEnterprise to Enterprise

b bbbFC

SANIP

InfrastructureSw itch /Router

Server Server

S torage S torage

FCSANSw itch /

Router

Server Server

S torage S torage

MAN / WAN

Storage Network Linkage

Departmental to Enterprise• Data distribution, upload, etc.

• Data protection

• Dynamic access based on demand frequency

• IP or FC based – depends on economics,

performance, administration, etc.

• Distance required – campus based vs. extended

distance

• Centralized management, security, etc.

Storage Network Linkage

Departmental to Enterprise

b bbbFC

SANIP

InfrastructureSw itch /Router

S erver S erver

S torage S torage

IPSANSw itch /

Router

S erver S erver

S torage S torage

MAN / WAN

Enterprise Operation Departmental Operation

Roadmap for Making Decisions Determine strategic

business requirements

• business environment dictates

requirements

Determine storage capacity

and expected growth

• benefit for implementing

storage network

• management costs with growth

Current operational

changes required

• short term and long term

• staffing and infrastructure

Getting StartedMake an informed

decision: use a solution

provider or roll your own

• expertise required

• who do you call when there

is a problem

• who’s going to manage this

• who guarantees it and will

make good

Become educated in

either case

Deployment Consider a phased

implementation

• new technology

introduction requires

learning curve

• asset protection

• ease of integration

• minimize risk

Start building

infrastructure

• physical plant

• skilled staff

Deployment Start with simple

configuration

• bring online first as shake-out

• make it local

• use the storage management

software chosen

• ensure common reporting

mechanisms

• make sure it works from the

console you’ve chosen

Build larger configuration

when satisfied

Get guarantee of

interoperability!!!

Deployment Test

• failure modes

• addition to capacity

• addition of servers

• addition of switches and

hubs

• service / maintenance

(7X24)

• performance

• normal operations

• degraded

• limits

• backup

• restore

Deployment

If solution provider is

also a storage vendor

- test replacement of

their storage device

with a competitor

Review your

management choice –

it is the most

important one to

make

Summary Many different solutions

• Many from companies with no experience in storage products

• Great deal of hype and mis-information now

One size does not fit all• Differing requirements

• Economics matter• Administration value• Extensibility – handle growth

Linking Storage Networks is important planning requirement• Multiple organizations involved

Critical decision for your company – choose wisely