network-attached storage chapter 7(5.3) nas(ismdr:beit:viii:chap5.3,madhu n. piit) 1

NAS(ISMDR:BEIT:VIII:Chap5.3,Madhu N. PIIT)

1

Network-Attached Storage

Chapter 7(5.3)


- 2

File Sharing Environment

• File system is structured way of storing and organizing data files

• File Sharing– Storing and accessing data files over network – FS must be mounted in order to access files

• Client/server model is implemented with file-sharing protocols for remote file sharing– Example: FTP, CIFS and NFS


- 3

File Sharing Technology Evolution

Network Attached Storage (NAS)

Stand Alone PC

Networked File Sharing

Networked PCsPortable Mediafor File Sharing


- 4

What is NAS ?NAS is shared storage on a network

infrastructure Clients

ApplicationServer

PrintServer NAS Device


- 5

General Purpose Servers vs. NAS Devices

Applications

Print Drivers

File System

Operating System

Network

File System

Operating System

Network

Single Function NAS Device

General Purpose Servers(Windows or UNIX)


- 6

Benefits of NAS

• Improves efficiency• Improved flexibility• Centralized storage• Simplifies management • Scalability• High availability – through native clustering• Provides security integration to environment

(user authentication and authorization)

NAS(ISMDR:BEIT:VIII:Chap5.3,Madhu N. PIIT) - 7

Components of NAS

Network Interface

NFS CIFS

NAS Device OS

Storage Interface

NAS Head

NFS

CIFS

UNIX

Windows

Storage Array

IP

NAS


- 8

NAS File Sharing Protocols

• Two common NAS file sharing protocols are:– CIFS – Common Internet File System protocol

• Traditional Microsoft environment file sharing protocol, based upon the Server Message Block protocol

– NFS – Network File System protocol• Traditional UNIX environment file sharing protocol


- 9

Network File System (NFS)

• Client/server application• Uses RPC mechanisms over TCP protocol• Mount points grant access to remote hierarchical file

structures for local file system structures• Access to the mount can be controlled by permissions

– NFS v2 was stateless and uses UDP as the transport layer protocol

– NFS v3 added TCP as an option for transport layer protocol– NFS v4 uses stateful protocol

• Aimed to provides support to cluster server deployment • Allow scalable parallel access to the files distributed among multiple

servers


- 10

NAS File Sharing - CIFS

• Common Internet File System– Developed by Microsoft in 1996– An enhanced version of the Server Message Block (SMB) protocol– Stateful Protocol

• Can automatically restore connections and reopen files that were open prior to interruption

– Operates at the Application/Presentation layer of the OSI model– Most commonly used with Microsoft operating systems, but is

platform-independent– CIFS runs over TCP/IP and uses DNS (Domain Naming Service) for

name resolution


- 11

IP Network NAS DeviceClient

Storage Interface

Network Protocol

NAS Operating System

NFS / CIFS

TCP/IP Stack

Network Interface

Application

Operating System

I/O Redirect

NFS / CIFS

TCP/IP Stack

Network Interface

1

3

2

4

Block I/O to storage device

Storage Array

NAS I/O


- 12

NAS ImplementationsIntegrated NAS

IP

NAS Device

NAS Gateway

NAS Head

IP FC SAN

Storage Array


- 13

Integrated NAS Connectivity

Application Server

Application Server

Integrated NAS System

Clients

IP


Gateway NAS Connectivity

Application Server

NAS Gateway

Storage Array

Application Server

IP FC SAN

Client

Client

Client


Hosting and Accessing Files on the NAS

Steps to host a file system:• Create an array volume• Assign volume to NAS device• Create a file system on the volume• Mount the file system• Access the file system

– Use NFS in UNIX environment• Execute mount/nfsmount command

– Use CIFS in windows environment• Map the network drive as: \\

Account1\Act_Rep


- 16

NAS Management

• Ships with vendor management software• Have unique management issues• Require preliminary analysis• Need additional complementary software


- 17

Managing NAS Environments

• Managing an Integrated System – Both NAS component and the storage array are

managed via NAS management software• Managing a Gateway System

– NAS component managed via NAS management software

– Storage array managed via array management software


- 18

Traditional File Server Environment – Example 1

Web Database Transaction

Mission Critical Servers

IP

FC SAN

Windows File Server

UNIX File Server

Internal Users

Business Clients Surfers, Shoppers


- 19

Storage Consolidation with NAS

Database Transaction

Mission Critical Servers

LAN/WAN

FC SAN

NAS Head

Internal Users

Surfers, ShoppersBusiness Clients


- 20

Traditional File Server Environment – Example 2

General purpose OS serving files viaFTP, CIFS, NFS, HTTP. . .

UNIX NTW2K

UNIX Windows

IP


- 21

Server Consolidation with NAS

NAS

General purpose OS serving files viaFTP, CIFS, NFS, HTTP. . .

UNIX Windows

IP


- 22

Chapter Summary

• Key topics covered in this chapter:– NAS Benefits– NAS Components– NAS File Sharing Protocols

• CIFS and NFS

– NAS Implementation• Integrated NAS• Gateway NAS

– NAS Management


- 23

Concept in Practice – EMC Celerra • Celerra is:

– Dedicated and high-performance infrastructure for file level I/Os

• Consists of:– Data Movers– Control Station– Specialized O/S (DART)

EMC Celerra NS-960 Integrated NAS

EMC Celerra NS40G (Gateway NAS)


- 24

Joining the Building Blocks - Integrated

Data Mover

Control Station

Internal Network Switch

Serial cable connect

Internal network connect

Fibre Channel storage connect

IP Network


- 25

Joining the Building Blocks - Gateway

Data Mover NAS NAS NAS NAS NAS NAS

Control Station

Serial cable connect

Internal network connect

Fibre Channel storage connect

IP Network

Fibre ChannelSwitch

SAN SAN SAN SAN SAN SAN

SAN Host(s)

Internal Network Switch

network-attached storage chapter 7(5.3) nas(ismdr:beit:viii:chap5.3,madhu n. piit) 1

Documents