nas foundation

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Copyright 2006 EMC Corporation. Do not Copy - All Rights Reserved.

NAS Foundations - 1

2006 EMC Corporation. All rights reserved.

NAS FoundationsNAS Foundations

Welcome to NAS Foundations.

The AUDIO portion of this course is supplemental to the material and is not a replacement for the

student notes accompanying this course.EMC recommends downloading the Student Resource Guide from the Supporting Materials tab, and

reading the notes in their entirety.

These materials may not be copied without EMC's written consent.

EMC believes the information in this publication is accurate as of its publication date. The information is subject to change

without notice.

THE INFORMATION IN THIS PUBLICATION IS PROVIDED AS IS. EMC CORPORATION MAKES NO

REPRESENTATIONS OR WARRANTIES OF ANY KIND WITH RESPECT TO THE INFORMATION IN THIS

PUBLICATION, AND SPECIFICALLY DISCLAIMS IMPLIED WARRANTIES OF MERCHANTABILITY OR

FITNESS FOR A PARTICULAR PURPOSE.

Use, copying, and distribution of any EMC software described in this publication requires an applicable software license.

EMC is a registered trademark of EMC Corporation.

All other trademarks used herein are the property of their respective owners.


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NAS Foundations - 2

2006 EMC Corporation. All rights reserved. NAS Foundations - 2

NAS Foundations

Upon completion of this course, you will be able to:

y Identify the concepts and value of Network Attached Storage

y List Environmental Aspects of NAS

y Identify EMC NAS Platforms and their differences

y Identify and describe Celerra Software Features

y Identify and describe Celerra Management Software offerings

y Identify and describe Windows Specific Options with respect to EMCNAS environments

y Identify and describe NAS Business Continuity Options with respectto the various EMC NAS platforms

The objectives for this course are shown here. Please take a moment to read them.


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NAS Foundations - 3


Network Attached Storage

y Identify what constitutes a NAS environment

NAS environment components are reviewed in this section.


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NAS Foundations - 4


What Is Network-Attached Storage

y Built on the concept of

shared storage on aLocal Area Network

y Leverages the benefitsof a network file serverand network storage

y Utilizes industry-standard network and

file sharing protocols

Network

File Server + Network-Attached Storage = NAS

App lication Application Application

Unix Client Unix ClientWindows Client

The benefit of NAS is that it now brings the advantages of networked storage to the desktop through

file-level sharing of data via a dedicated device.

NAS is network-centric and typically used for client storage consolidation on a variety of networktopologies such as LANs (Local Area Network), MANs (Metropolitan Area Network), WANs (Wide

Area Network), etc. NAS is a preferred storage capacity solution for enabling clients with unregulated

access to files quickly and directly via purpose built data sharing equipment. This eliminates several

bottlenecks users often encounter when accessing files from a general-purpose servers. In addition,

NAS can serve UNIX and Microsoft Windows users seamlessly, sharing the same data between the

different architectures.

NAS provides security and performs all file and storage services through standard network protocols:

y TCP/IP for data transfer

y Ethernet and Gigabit Ethernet for media access

y CIFS, http, ftp, and NFS for remote file service


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NAS Foundations - 5


Why NAS?

y Highest availability

y Scales for growth

y Avoids file replication

y Increases flexibilityy Reduces complexity

y Improves security

y Reduces Costs

Firewall

Web

Servers

NAS

Internet

Data CenterSn

S2

.

..

.

S1

Internal

Network

Through the advent of NAS applications that use file system level access, the data can now be shared

to large numbers of users, that may be geographically dispersed, simultaneously. Therefore many users

can now take advantage of the availability and scalability of networked storage. Centralizing file

storage can reduce system complexity and system administration costs, along with simplifying backup,restore, and disaster recovery solutions.

Although NAS trades some performance for manageability and simplicity, it is by no means a lazy

technology. Gigabit Ethernet allows NAS to scale to high performance and low latency, making it

possible to support a myriad of clients through a single interface. Many NAS devices support multiple

interfaces and can support multiple networks at the same time.


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NAS Foundations - 6


NAS Operations

y Traditional IO operations use filelevel IO protocols

y File system is mounted remotelyusing a network file accessprotocol, such as:Network File System (NFS) for Unix

Common Internet File System(CIFS)for

Microsoft Windows

y IO is redirected to remote system

y Utilizes mature data transport (e.g.,TCP/IP) and media accessprotocols

y NAS device assumes responsibilityfor organizing data (R/W) on diskand managing cache

Disk

IP Network

App lication

NAS Device

NAS

SANORDirect

Attach

One of the key differences of a NAS disk device, compared to DAS or other networked storage

solutions such as SAN, is that all traditional I/O operations use file level I/O protocols. File I/O is a

high level type of request that, in essence, specifies only the file to be accessed, but does not directly

address the storage device. The client file I/O is converted into block level I/O by the NAS deviceoperating system to retrieve the actual data. Once the data has been retrieved it is once again converted

back to file level I/O for return to the client.

A file I/O specifies the file. It also indicates an offset into the file. For instance, the I/O may specify

Go to byte 1000 in the file (as if the file were a set of contiguous bytes), and read the next 256 bytes

beginning at that position.

Unlike block I/O, there is no awareness of a disk volume or disk sector in a file I/O request. Inside the

NAS appliance, the operating system keeps tracks of where files are located on disk. The OS issues a

block I/O request to the disks to fulfill the file I/O read and write requests it receives.

The disk resources can be directly attached to the NAS device or using a SAN, referred to as agateway configuration.

Block level IO support by NAS devices is discussed later in this module.


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NAS Foundations - 7


NAS Architecture

Application

Remote I/O

request

Operating System

NFS/CIFS

TCP/IP Stack

Network Interface

File I/O to NAS

I/O Redirector

Network Interface

TCP/IP Stack

Network FileProtocol Handler

NASOperatingSystem

To Storage

NFS and CIFS handle file

requests to remote filesystem

I/O is encapsulated byTCP/IP Stack to moveover the network

NAS device convertsrequests to block IO andreads or writes data toNAS disk storage

Drive Protocol (SCSI)

Storage Network

Protocol(Fibre Channel)

The Network File System (NFS) protocol and Common Internet File System (CIFS) protocol handle

file I/O requests to the remote file system, which is located in the NAS device storage. I/O requests are

packaged by the initiator into the TCP/IP protocols to move across the IP network. The remote NAS

file system converts the request to block I/O and reads or writes the data to the NAS disk storage. Toreturn data to the requesting client application, the NAS appliance software re-packages the data to

move it back across the network.

Here we see an example of an IO being directed to the remote NAS device and the different protocols

that play a part in moving the request back and forth to the remote file system located on the NAS

server.


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NAS Foundations - 8


NAS Device

y Single-purpose machine orcomponent, serves as a dedicated,

high-performance, high-speedcommunication of data using bothfile level and block level IO

y Is sometimes called a filer or anetwork appliance

y Uses one or more NetworkInterface Cards (NICs) to connectto the customer network

y Uses proprietary optimizedoperating system; DART, Data

Access in Real Time

y Uses industry standard storageprotocols to connect to storageresources Disk

Storage

IP Network

Client Application

NAS Device

Network Drivers and Protocols

NFS CIFS

NAS Device OS (DART)

Storage Drivers and Protocols

A NAS server is not a general-purpose compute. NAS devices use a significantly streamlined/tuned OS

in comparison to general purpose computer. It is sometimes called a filer because it focuses all of its

processing power solely on file service and file storage. The NAS device is sometimes called a

network appliance, referring to the plug and play design of many NAS devices. Common networkinterface cards (NICs) include gigabit Ethernet (1000 Mb/s) or Fast Ethernet (10Mb/s), ATM, and

FIDDI. Most NAS devices also support NDMP (Network Data Management Protocol) for backup,

Novell Netware, FTP and HTTP protocols.

The NAS operating system for Network Appliance products is called Data ONTAP. The NAS

operating system for EMC Celerra is DART - Data Access in Real Time. These operating systems

are tuned to perform file operations including open, close, read, write, etc.

The NAS device generally uses a standard drive protocol, some form of SCSI, to manage data to and

from the disk resources.


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NAS Foundations - 9


NAS Applications

y CAD/CAM environments, wherewidely dispersed engineers have toshare and modify design drawings

y Serving Web pages to thousandsof workstations at the same time

y Easily sharing company-wideinformation among employees

y Database application

Low transaction rate

Low data volatilitySmaller in size

Not performance constrained

Database applications have traditionally been implemented in a SAN architecture. The primary reason

is the conclusive performance of a SAN. This characteristic is especially applicable for very large, on-

line transactional applications with high transaction rates and high data volatility.

However, NAS might be appropriate where the database transaction rate is low and performance is not

constrained. Extensive application profiling should be done in order to understand the specific

database application requirement and, if in fact, a NAS solution would be appropriate.

When considering a NAS solution, the databases should:

ybe sequentially accessed, non-indexed or have a flat file structure

y have a low transaction rate

y have low data volatility

ybe relatively small

y not have performance / timing constraints

y require multiple dynamic path access to application servers


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NAS Foundations - 10


NAS Environment

y Identify components in a common networking

environment

Key components of NAS and networking infrastructure are reviewed in this section.


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Terminology

y Ethernet: Local network protocol that uses coaxial or

twisted pair cablesy Network Topology: Geometric arrangement of nodes and

cable links in a LAN; used in two general configurations:bus and star

y Protocol: Defines how computers identify one another ona network, the form that the data should take in transit,and how this information is processed once it reaches its

final destination

y IP Address: Unique number that identifies a computer toall other computers connected to the network

Ethernet is a local-area network protocol that uses coaxial or twisted pair cables as a means for

communication. Ethernet is popular because it strikes a good balance between speed, cost, and ease of

installation. These benefits, combined with wide acceptance in the computer marketplace and the

ability to support virtually all popular network protocols, make Ethernet an ideal networkingtechnology for most computer users today.

A network topology is the geometric arrangement of nodes and cable links in a LAN, and is used in

two general configurations: bus and star.

A protocol defines how computers identify one another on a network, the form that the data should

take in transit, and how this information is processed once it reaches its final destination. TCP/IP is a

common protocol used in sending information via the Internet. Protocols also define procedures for

handling lost or damaged transmissions, or "packets.

An Internet Protocol (IP) address is a four octet number in the commonly used IP version 4, for

example 155.10.20.11, that uniquely identifies a computer to all other computers connected to thenetwork.


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What is a Network?

y LAN

y Physical Media

y WAN

y MAN

Site 1

Site 2

LAN

A network is any collection of independent computers that communicate with one another over a shared network medium.

LANs are networks usually confined to a geographic area, such as a single building or a college campus. LANs can be

small, linking as few as three computers, but often linking hundreds of computers used by thousands of people.

Physical Media

An important part of designing and installing a network is selecting the appropriate medium. There are several types in use

today: Ethernet, Fiber Distributed Data Interface (FDDI), Asynchronous Transfer Mode (ATM), and Token Ring.

WAN

Wide area networking combines multiple LANs that are geographically separate. Services such as dedicated leased phone

lines, dial-up phone lines (both synchronous and asynchronous), satellite links, and data packet carrier services connect the

different LANs. Wide area networking can be as simple as a modem and remote access server for employees to dial into, or

it can be as complex as hundreds of branch offices globally linked using special routing protocols and filters to minimize

the expense of sending data over vast distances.

MANMetropolitan area networking is a networking infrastructure size that falls in-between a LAN and a WAN. They are

generally used to consolidate networking infrastructures in a campus sized, generally between five (5) and fifty (50)

kilometers in diameter, area to provide sharing of localized resources. They typically use wireless or optical

interconnections between localized sites within the MAN. The IEEE 802.6 standard specifies the unique way that the MAN

can communicate between sites to minimize latency and congestion. This is known as a distributed queue dual-bus network,

(DQDB), which utilizes a dual bus, distributed queuing.


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Physical Components

y Network

InterfaceCard (NIC)

y Switches

y Routers

NIC

NIC

NIC

NIC

Switch

Switch

Router

155.10.10.XX

155.10.20.XX

Network Interface Card

Network interface cards, commonly referred to as NICs, are used to connect a Host, Server,

Workstation, PC, etc. to a network. The NIC provides a physical connection between the networkingcable and the computer's internal bus. The rate at which data passes back and forth can be different.

Switches

LAN switches can link multiple network connections together. Todays switches accept and analyze

the entire packet of data to catch certain packet errors and keep them from propagating through the

network before forwarding it to its destination. Each of the segments attached to an Ethernet switch has

the full bandwidth of the switch 10Mb/100Mb/1Gigabit.

Routers

Routers pass traffic between networks. Routers also divide networks logically instead of physically. An

IP router can divide a network into various subnets so that only traffic destined for particular IP

addresses can pass between segments.


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Network Protocols

y Network transport Protocols

Universal Datagram Protocol (UDP) for non-connectionoriented networks

Transmission Control Protocol (TCP) for connection

oriented networks

y Network filesystem Protocols

NFS to manage files in a networked Unix environmentCIFS to manage files in a networked Windows environment

Network transport protocols are standards that allow computers to communicate. They are used to

manage the movement of data packets to devices communicating across the network. UDP and TCP

are examples of transport protocol.

In a non-connection oriented communication model, the data is sent out to a recipient using a best

effort approach with no acknowledgement of the receipt of the data being sent back to the originator

by the recipient. Error correction and resend must be controlled by a higher layer application to ensure

data integrity.

In a connection oriented model, all data packets sent by an originator are acknowledged by the

recipient and transmission errors / lost data packets are managed at the protocol layer.

TCP/IP (for UNIX, Windows NT, Windows 95 and other platforms), IPX (for Novell NetWare),

DECnet (for networking Digital Equipment Corp. computers), AppleTalk (for Macintosh computers),

and NetBIOS/NetBEUI (for LAN Manager and Windows NT networks) are examples of network

transport protocols in use today.

Network filesystem protocols are used to manage how data requests are processed once it reaches its

final destination. Both NFS and CIFS support UDP and TCP transport protocols.

Network block level protocols are discussed later in this presentation.


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Network Addressing

y IP Addressing

y DHCP

y DNS

155.10.10.13Host Name Peter

155.10.10.11

Switch

Router

155.10.20.11

DNS Server

155.10.10. 14

Host name Mary

Host Name = Account1

155.10.10.XX

155.10.20.XX

DHCPServer

155.10.10.12

Several things must happen in order for computers to be able to communicate data across the network.

First, the computer must have a unique network address, referred to as the IP Address.

An address can be assigned in one of two ways; dynamically or statically. A static address requiresentering the IP address that the computer uses in a local file. However, if two computers on the same

subnet are assigned the same IP address, they would not be able to communicate. Another approach is

to set up a computer on the network to dynamically assign an IP address to a host when it joins the

network. This is called the Dynamic Host Configuration Protocol (DHCP Server).

In our example, the host Mary is assigned an IP address 155.10.10.14, and the host Peter is assigned

an IP address 155.10.10.13 by the DHCP server. The NAS device, Account1, is a File server. Servers

normally have a statically assigned IP address. In this example, it has the IP address 155.10.20.11.

A second requirement for communications is to know the address of the recipient of the

communication. The more common approach is to communicate by name, for example, the name you

place on a letter. However, the network uses numerical addresses. A more efficient solution is theDomain Name Service (DNS). The DNS is a hierarchical database, which resolves host names to IP

addresses. In our example, if someone on host Mary wants to talk to host Peter, it is the DNS server

that resolves Peter to 155.10.20.13.


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Volume and Files

y CreateVolumesVolume

y CreateNetwork

Filesystem

155.10.10.13

Host Name Peter

155.10.10.11

Router

DNS Server

155.10.10. 14Host name Mary

Account1

Array

/Acct_ RepFile System

NAS

155.10.20.11

DHCP

Server

155.10.10.12

Create Array Volume

The first step in a network attached storage environment is to create logical volumes on the array andassign it a LUN Identifier. The LUN is then presented to the NAS device.

Create NAS Volume

The NAS device performs a discovery operation when it first starts or when directed. In the discoveryoperation, the NAS device sees the array LUN as a physical drive. The next task is to create logicalvolumes at the NAS device level. The Celerra creates meta volumes using the volume resourcespresented by the array.

Create Network File

When the logical volumes are created on the Celerra, it can use them to create a file system.

In this example, we have created a file system /Acct_Rep on the NAS server Account1.

Mount File System

Once the file system has been created, it must be mounted. With the file system mounted, we can thenmove to the next step, which is publishing the file system on the network.


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Publish

y Export

y Share

155.10.10. 13Host name Peter

User PeterUnixExport

155.10.10.11

Router

DNS Server

155.10.10. 14Host name MaryUser MaryMS Windows

Share

Array

ACCOUNT1 /Acct_ Rep

155.10.20.11

Group Name =SALES

Group Name =Accounting

NAS

DHCPServer

155.10.10.12

Now that a network file system has been created and mounted, there are two ways it can be accessed

using the network.

The first method is through the UNIX environment using NFS. This is accomplished by performing anExport. The Export publishes to those UNIX clients who can mount (access) the remote file

system. Access permissions are assigned when the export is published.

The second method is through the Windows environment using CIFS. This is accomplished by

publishing a share. The share publishes to those Windows clients who map a drive to access the

remote file system. Access permission are assigned when the share is published.

In our example, we may only allow Mary and Peter, who are in the Sales organization, share or

export access. At this level, NFS and CIFS are performing the same function but are used in

different environments. All members of the Group SALES, which include the users Mary and Peter,

are granted access to /Acct_Rep.


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Client Access

yMount

yMAP

155.10.10. 13

Host name PeterUser Peter

Unix

nfsmount

155.10.10.11

Router

DNS Server

155.10.10. 14Host name MaryUser Mary

MS Windows

MAP

Array

ACCOUNT1 /Acct_ Rep

155.10.20.11

Group Name =SALES


NAS

DHCPServer

155.10.10.12

To access the network file system, the client must mount a directory or map a drive pointing to the remote file

system.

Mount is a UNIX command performed by a UNIX client to set a local directory pointer to the remote file system.

The mount command uses NFS protocol to mount the export locally.

For a UNIX client to perform this task, it executes the nfsmount command. The format for the command is:

y nfsmount /name of the NAS server:name of the remote file system/name of the local directory

For example:

y nfsmount/Account1:Acct_Rep /localAcct_Rep.

For a Windows client to perform this task, it executes a map network drive. The sequence is my computer>

tools>map network drive. Select the drive letter and provide the server name and share name in the Folderfield.

For example:

y G:

y \\Account1\Acct_Rep

If you make a comparison, the same information is provided: the local drive (Windows) or the local directory and

the name of the NAS server and the name of the export or the share.


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File Permissions

y Create File

y File Request

155.10.10. 13

Host name PeterUser Peter

Unix

155.10.10.11

Router

DHCPServerDNS Server

155.10.10. 14Host name MaryUser Mary

MS Windows

155.10.10.12

Array155.10.20.11

Group Name =SALES


Account1

/Acct_ Rep

MRPT1 PRPT2Files

NAS

Create file

Once access is gained by the client, files can be created on the remote file system. When a file is

created by a client, normal permission is assigned. The Client can also modify the original permissionsassigned to a file. File permission is changed in UNIX using the chmod command. File permission in

Windows is changed through right clicking on the selected file, then selecting Properties> Security add

or remove group add or remove permissions. It should be noted that in order to modify the file

permissions, one must have the permission to make the change.

File request

If a request for a file is received by the NAS server, the NAS server first authenticates the user locally

or over the network. If the user identity is confirmed, then the user is allowed to perform operations

contained in the file permissions of the users Group.

In our example, user Mary on host Mary creates a file MRPT1 on the NAS server Accout1. She assigns

herself the normal permission for this file, which allows her to read and write to this file. She also

limits file permissions to other members of the Group Sales to read only. User Peter on host Peter is a

member of the Group SALES. Peter has access to the export / Acct_Rep. If user Peter attempts to

write to file MRPT1, he would be denied the permission to write to the file.


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EMC NAS Platforms

y Identify products from the EMC NAS range of equipment

EMC NAS products are reviewed in this section.


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EMC Celerra PlatformsBroadest Range of NAS Products

SIMPLE WEB-BASED MANAGEMENT

CLARiiON, Symmetrix

NAS gateway to SAN

One or twoData Movers

* X-Blade Technology

High availability

NS40G*NS500G

NS700G

NSXNS704GNS80G*

NS704

NS350

NS40*NS500

NS700

Advanced clusteringAdvanced clusteringAdvanced clusteringHigh availability

CLARiiON, SymmetrixCLARiiON, SymmetrixIntegratedCLARiiON

IntegratedCLARiiON

NAS gateway to SANNAS gateway to SANUpgradeableto gateway

Upgradeableto gateway

Four to eightX-Blades

Four Data Movers* X-Blade Technology

Four Data MoversOne or two

Data Movers* X-Blade technology

An important decision you must make is, What is the right information platform that meets my

business requirements?

EMC makes it easy by offering the broadest range of NAS platforms in the industry. Rate yourrequirements and choose your solution.

The range of EMC NAS all use DART, Data Access in Real Time, operating system, which is

specially developed to provide efficient data transfer between the front end network connections and

the backend disk interfaces. There are at present two configurations available, Gateway and Integrated.

The Gateway models provide a NAS interface to SAN/Fabric attached storage arrays, while the

Integrated have their storage arrays contained within the same frames as the NAS heads, Data Movers,

which are solely dedicated to NAS functionality, (no shared host access to disks).

The Celerra NS Gateway (can be configured with up four Data Movers) and the Celerra NS GS

(configured with a single Data Mover) connects to CLARiiON CX arrays and/or Symmetrix DMX

arrays through a fibre channel switch or directly connected (in the case of CLARiiON).

The NSX gateway model can be configured with between four and eight Data Movers.


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Celerra NAS - SAN Scalabil ity

y Consolidated storageinfrastructure for allapplications

y NAS front end scalesindependently of SANback end

y Allocate storage toCelerra and servers asneeded

y Centralized managementfor SAN and NAS

y iSCSI gateway to SANWindows

UNIX

CLARiiON

CX Family

ConnectrixSAN

SymmetrixDMX Family

Celerra NS GFamily

Celerra NSX

One of the reasons that EMC NAS scales impressively is due to the gateway architecture that separates

the NAS front end (Data Movers) from the SAN back end (Symmetrix or CLARiiON).

This allows the front end and back end to grow independently. Customers can merely add Data Moversto the EMC NAS to scale the front-end performance to handle more clients. As the amount of data

increases, you can add more disks, or the EMC NAS can access multiple Symmetrix or CLARiiON.

This flexibility leads to improved disk utilization.

EMC NAS supports simultaneous SAN and NAS access to the CLARiiON and Symmetrix. and can be

added to an existing SAN, with general purpose servers now able to access non-NAS back-end

capacity. This extends the improved utilization, centralized management, and TCO benefits of SAN

plus NAS consolidation to EMC NAS, Symmetrix, and CLARiiON.

The configuration can also be reconfigured via software. Since all Data Movers can see the entire

file space, it is easy to reassign filesystems to balance the load. In addition, filesystems can be

extended online as they fill.

Even though the architecture splits the front end among multiple Data Movers and a separate SAN

back end, the entire NAS solution can be managed as a single entity.


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Celerra Family Hardware

y Describe and identify common EMC NAS components

Due to the diversity of the range of EMC NAS systems we now briefly review some of the major

hardware components, to differentiate between the various options available.


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Celerra NS Family Control Station Hardware

yThe control station provides an interface to the control; to

manage and configure the NAS solution

Control Station provides the controlling subsystem of the Celerra, as well as the management interface

to all file server components. The Control Station provides a secure user interface as a single point of

administration and management for the whole Celerra solution. Control Station administrative

functions are accessible via the local console, Telnet (not recommended), or a Web Browser.

The Control station is single Intel processor based, with high memory capacity. Dependent on the

model, the Control Stations may have internal storage. The local LAN switch provides the internal

communications network for the Data Movers and the Control Station and should NOTbe integratedinto a client networking infrastructure.

Within the NSX model there are no serial interconnections between the Control Station and the Data

Movers and the internal switch has been built into the Control Station functionality.


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NSX Next Generation Control Station

y Celerra NSX Front view

LEDs and Switches

Power Switch

NMI Switch

Reset Switch ID Switch

Power Boot Sequence LED

Status LED

HDD Act LED

HDD Fault LED Gb #1 and Gb #2 LED

USB Connectors 2 and 3

ID LED

Serial Port COM2

The Control Station is a dedicated management Intel processor-based computer that monitors and

sends commands to the blades. The private network connects the two Control Stations (always shipped

on NSX systems) to the blades through the system management switch modules. Like previous

versions it provides software installation and upgrade services, and high-availability features such asfault monitoring, fault recovery, fault reporting (CallHome), and remote diagnosing. Two Control

Stations can be connected to a public or private network for remote administration. Each Control

Station has a serial port that connects to an external modem so that the Control Station can call home

to EMC or a service provider if a problem should arise.


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NSX Next Generation Control Station

y Celerra NSX Rear view

eth3 - PublicLAN Port

COM1 - To serialmodem (for Call-Home)

eth0 Internal Network(To Mgmt. Switch-A in

Enclosure 0)

Video Port

Gb2 Internal Network(To Mgmt. Switch-B in

Enclosure 0)

Gb1 IPMI(To eth1 of the other

Control Station)

This slide displays the rear view of the Next Generation Control Station. Note the lack of a 25-pin

quad serial port and spider cable.


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Celerra Family Data Mover Hardware

y Single or Dual IntelProcessors

y PCI or PCI-X based

y High memory capacity

y Multi-port Network cards

y Fibre Channel connectivityto storage arrays

y No internal storage devices

y Redundancy mechanism

Fibre I/O module GbE I/O module

NSX Data Mover/ NS80G Data Mover

NS40 Data Mover

Each Data Mover is an independent, autonomous file server that transfers requested files to clients and

are managed as a single entity. Data Movers are hot pluggable and can be configured with standbys to

implement N to 1 unaffected should a problem arise with another Data Mover. The multiple Data

Movers (up to 8 in the NSX and 4 in the NS range availability. A Data Mover (DM) connects to a LANthrough FastEthernet and/or Gigabit Ethernet.

The default name for a Data Mover is server n, where n was its original slot location in the first NAS

frames. This has been continued into the new frames and the naming convention remains slot

related. For example, in the Golden Eagle/ Eagle frame, a Data Mover can be in slot location 2

through 15 (i.e. server_2 - server_15), therefore the first Data Mover is any frame remains server_2,

the second server_3, etc.

There is no remote login capability on the DM, nor do they run any binaries (very secure) and all

access to the Data Mover for management and configuration must be performed via the Control

Station.

Data Mover redundancy is the mechanism by which the Celerra family reduces the network data

outage in the event of a Data Mover failure. The ability to failover the Data Movers is achieved by the

creation of a Data Mover configuration database on the Control Station system volumes and is

managed via the Control Station. No Data Mover failover occurs if the Control Station is not available

for some reason.


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Celerra Family Data Mover Hardware (Cont.)

y Standby Data Mover Configuration Options

Each standby Data Mover, as a standby for a single primary DataMover

Each standby Data Mover, as a standby for a group of primary DataMovers

y Failover Operational Modes

Automatic

Retry

Manual

These Standby Data Movers are powered and ready to assume the personality of their associated Primary Data Movers in

the event of a failure. If a Primary Data Mover fails, the Control Station detects the failure and initiates the failover process.

The failover procedure, in an Automatic configuration, is as follows.

The Control Station:1. Removes power from the failed Data Mover.

2. Sets the location for the Standby Data Mover to assume its new personality in the configuration database.

3. Controls the personality take over and allows the Standby Data Mover to assume the primary role, thereby enabling

clients to re-access their data transparently via the standby.

Once the failed Data Mover is repaired, the failback mechanism is always manually administrator initiated. This process is

the reverse of the failover process and restores the primary functionality to the repaired Primary Data Mover and returns the

Standby Data Mover into its standby state in preparation for any future outage.

There are three operational modes of operation for Failover: Automatic, Retry, and Manual.

1. Automatic Mode: Control Station detects the failure of a Data Mover. The failover process occurs without trying any

recovery process first.

2. Retry Mode: Control Station detects the failure, an attempt to reboot the failed Data Mover is tried first before thefailover procedure is initiated.

3. Manual Mode: Control Station detects the failure and removes power from the failed Data Mover. However, no further

Data Mover recovery action is taken until administrative intervention. Recovery after a Data Mover failover is always

a manual process.


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NAS Reference Documentation

yNAS Interoperability

MatrixData Movers

Control Stations

Software supported features

yWebsite

www.emc.com/horizontal/interoperability

The NAS interoperability Guide provides support information on the Data Movers and Control Station

models, NAS software version, supported features, storage models, and microcode. This

interoperability reference can be found at: http://www.emc.com/horizontal/interoperability.


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Celerra Family Software

y Describe operating systems used by EMC NAS

Having briefly reviewed some of the major hardware components, the software environment of the

high-end EMC NAS offering is covered next.


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Celerra Software Operating Systems

y EMC LinuxThis is an industry hardened and EMC modified Operating System loaded on the

Control Station to provide: Secure NAS management environment Growing in popularity and corporate acceptance

y DART Data Access in Real TimeThis is a highly specialized Operating System designed to optimize network

traffic Input/Output throughput and is loaded on the Data Movers

Is multi-threaded to optimize load balancing capabilities of the multi-processorData Movers

Advanced volume management - UxFS Large file size and filesystem support

Ability to extend filesystems online

Metadata logging for fast recovery

Striped volume support

Feature rich to support the varied specialized capabilities of the Celerra range Data Mover Failover

Networking functionality Port Aggregation, FailSafe Network device, multi-protocol support

Point in time Filesystem copies

Windows environmental specialties

EMC Linux OS is installed on the Control Station. Control Station OS software is used to install,

manage, and configure the Data Movers, monitor the environmental conditions and performance of all

components, and implement the Call Home and dial-in support feature. Typical Administration

functions include the volume and filesystem management, configuration of network interfaces,creation of filesystems, exporting filesystems to clients, performing filesystem consistency checks, and

extending filesystems.

The OS that the Data Movers run is EMCs Data Access in Real Time (DART) embedded system

software, which is optimized for file I/O, to move data from the EMC storage array to the network.

DART supports standard network and file access protocols: NFS, CIFS, and FTP.


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Celerra Family Software Management

y Describe user interfaces available for EMC NAS

management

The two user interfaces available for EMC NAS management are reviewed in this section.


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Celerra Management Command Line

yThe command line can be accessed on the Control

Station viaAn ssh interface tool (i.e. PuTTy)

Telnet

y Its primary function is for scripting of common repetitivetasks that may run on a predetermined schedule to easeadministrative burden

y It has approximately 80 UNIX command-like commands

Telnet access is disabled, by default, on the Control Station due to the possibility of unauthorized

access if the Control Station is placed on a publicly accessible network. If this is the case, it is strongly

recommended that this service is not enabled.

The preferred mechanism of accessing the Control Station is the SSH (Secure Shell) daemon via an

SSH client such as PuTTy.


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Celerra Manager Management

GUI management has become consolidated into one product with two options; Celerra Native Manager

Basic Edition and Celerra Management Advanced Edition.

The Basic Edition is installed, along with the DART OS, and provides a complete set of commonmanagement functionality for a single Celerra at a time. The Advanced Edition adds multiple Celerra

support, along with some advanced feature GUI management, and is licensed separately from the

DART code.


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Celerra Manager Wizards

Celerra Manager offers a number of configuration Wizards for various tasks to assist with new

administrator ease of implementation.


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Celerra Manager Tools

Celerra Manager offers a set of tools to integrate Celerra monitoring functionality and launch

Navisphere Manager.

With the addition of the Navisphere Manager Launch capability, the SAN/NAS administrator has amore consolidated management environment.


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EMC ControlCenter V5.x.x NAS Support

y Discovery and Monitoring

Data MoversDevices and volumes

Network adapters and IPinterfaces

Mount points

Exports

Filesystems (includingsnapshots and checkpoints)

The EMC flagship management product, EMC ControlCenter, has the capability of an assisted

discovery of both EMC NAS and third party NAS products, namely NetApps filers

Currently, management of the EMC NAS family is deferred to the specific product managementproducts due to the highly specialized nature of the NAS environment. Therefore, this product

functionality (shown on this slide) is focused mainly around discovery, monitoring, and product

management software launch capability

ControlCenter V5.x.x has enhanced device management support for the Celerra family. The

ControlCenter Celerra Agent runs on Windows and has enhanced discovery and monitoring

capabilities. You can now view properties information on Celerra Data Movers, devices, network

adapters and interfaces, mount points, exports, filesystems (including snapshots and checkpoints), and

volumes from the ControlCenter Console. You can also view alerting information for the Celerra

family as well.


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Celerra Family Software Management

y Describe the implementation of VLANs (Virtual Local

Area Networks) for environmental management with EMCNAS

Next, an overview of the virtual local area networking environment, or VLANs, is reviewed.


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VLAN Support

y Create logicalLAN segment Divide a single

LAN into logicalsegments

J oin multipleseparatesegments into onelogical LAN

y VLAN Tagging 802.1q

y Simplified

Management No network

reconfigurationrequired formemberrelocation

Hub Hub

Hub Hub

Bridge

or

Switch

Bridge

or

Switch

Hub Hub

Router

Workstation VLAN B

VLAN B

VLAN A

VLAN A

Collision Domain

LAN Segment

Collision DomainLAN Segment

Collision Domain

LAN Segment

Broadcast Domain

LAN

Broadcast Domain LAN

Network domains are categorized into Collision, a LAN segment within which data collisions are contained, or Broadcast,

the portions of the network through which broadcast and multicast traffic is propagated. Collision domains are determined

by hardware components and how they are connected together. The components are usually client computers, hubs, and

repeaters. A network switch or a router that generally does not forward broadcast traffic separates a Collision domain from

a Broadcast domain. VLANs allow multiple, distinct, possibly geographically separate network segments to be connected in

to one logical segment. This can be done by subnetting or using VLAN tags (802.1q.), which is an address added to

network packets to identify the VLANs to which the packet belongs. This could allow servers that were connected to

physically separate networks to communicate more efficiently and it could prevent servers that were attached to the same

physical network from impeding one another.

By using VLANs to logically segment the Broadcast Domains, the equipment contained within this logical environment

need not be physically located together. This now means that if a mobile client moves location, an administrator need not

do any physical network or software configuration for the relocation as bridging technology would now be used, and a

router would only be needed to communicate between VLANS.

There are two commonly practiced ways of implementing this technology:

1. IP Address subnetting or

2. VLAN Ethernet packet tagging

When using the IP address subnetting methodology, the administrator configures the broadcast domains to include the

whole network area for specific groups of computers by using BridgeRouter technology. When using the VLAN tagging

methodology, the members of a specific group have an identification tag embedded into all of their Ethernet packet traffic.

VLAN Tagging allows a single Gigabit Data Mover port to service multiple logical LANs (Virtual LANs). This allows data

network nodes to be configured (added and moved as well as other changes) quickly and conveniently from the

management console, rather than in the wiring closet. VLAN also allows a customer to limit traffic to specific elements of a

corporate network and protect against broadcasts (such as denial of service) affecting whole networks. Standard router

based security mechanisms can be used with VLANs to restrict access and improve security.


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VLAN Benefits

y Performance

y ReducedOverhead

y Reduced Costs

y Security

VLAN-A VLAN S VLAN E

The benefits of VLAN support include:

y Performance: In all networks, there is a large amount of broadcast and multicast traffic and

VLANS can reduce the amount of traffic being received by all clients.

y Virtual Collaborative Work Divisions: by placing widely dispersed collaborative users into a

VLAN, broadcast and multicast traffic between these users are kept from affecting other network

clients and reduce the amount of routing overhead placed on their traffic.

y Simplified Administration: with the large amount of mobile computing today, physical user

relocation generates a lot of administrative user reconfiguration (adding, moving and changing). If

the user has not changed company functionality, but has only relocated, VLANs can achieve

undisrupted job functionality.

y Reduced Cost by using VLANS: expensive routers and billable traffic routing costs can be reduced.

y Security, by placing users into a tagged VLAN environment, external access to sensitive broadcast

data traffic can be reduced.

VLAN support enables a single Data Mover with Gigabit Ethernet port(s) to be the standby for

multiple primary Data Movers with Gigabit Ethernet port(s). Each primary Data Mover's Gigabit

Ethernet port(s) can be connected to different switches. Each of these switches can be in a different

subnet and different VLAN. The standby Data Mover's Gigabit Ethernet port is connected to a switch

which is connected to all the other switches.


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Celerra Family Filesystem Management

y Describe filesystem Quotas implementation on EMC NAS

Next, file system controls supported by Celerra Management software are reviewed.


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Filesystem Controls - User Quota Restrictions

yThere are three main types of quotas used in data space

control:Soft Quota

Amount of data space or number of files used under normal workingconditions

Hard Quota

Total space or number of files a user/group can use or create ona filesystem

Tree Quota

Total space or number of files that a user/group can use or create on a

data directory tree. They are used as a logical mechanism to segmentlarge file systems into smaller administrative portions that do not affecteach others operation

One of the most common concerns in a distributed data environment is that users tend to save many

copies of the same information. When working in a collaborative distributed environment, the amount

of data space required by each user expands rapidly and, in some cases, uncontrollably. To minimize

data space outages, the user space can be controlled by imposing Quotas on users, or groups of users,to limit the number of blocks of disk space they can use or the number of files they can create.

The Soft Quota is a logical limit placed on a user that can be exceeded without the need for any

administrative intervention. Once the soft quota limit has been exceeded, the user has a grace period to

use the extra space defined by the hard quota limit. However, the user/group cannot exceed the hard

limit

The grace period is a time limit during which the user, or group, can continue to increase the amount of

disk space used or number of files created. If the grace period expires, the user/group must reduce the

amount of space used or the number of files to below the soft limit before any new space or files can

be created.

The Celerra family supports all of these Quota methodologies, thereby assisting administrators used to

these management tools, with a seamless transition into an EMC NAS environment.


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Celerra Family Management Software

y Describe some Windows-specific options for

environmental management using EMC NAS including:Usermapper

Virtual Data Movers

Microsoft Management Console Snap-ins

Celerra family high availability features are reviewed in this section.


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Usermapper Windows and UNIX integration

y Usermapper is the methodology by which Windows SIDs

(Security Identifiers) are equated with UNIX UIDs(User/Group Identifiers) on EMC NAS devices

yThere are two configurable environments to achievethese mappings

Internal

Part of the Data Mover's software. It does not require a separateinstallation or additional configuration procedures for a new CelerraNetwork Server

ExternalRuns as a daemon on a Celerra Control Station. Requires a separate

installation as well as additional configuration and managementprocedures

EMC NAS device Data Mover operating system, DART, utilizes a very specialized UNIX like file

system and thus has the same security structures. To support disparate clients, NFS and CIFS, the

various environmental security structures need to be equated to the Data Mover structures. In the NFS

environment no translation needs to be performed, however in the Microsoft environment the SecurityIdentifiers, (SID), need to be equated to the security structures on the filesystem. Usermapper is the

mechanism that is used in an EMC NAS device to achieve this mapping.


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Usermapper Windows and UNIX integration (Cont.)

y Other considerations about choosing the Usermapper

methodology is determined by the client environmentWindows only

Internal Usermapper in Windows-only environments is recommended.Celerra Network Server installations after version 5.2 use this by default

Mixed protocol UNIX and Windows

In multiprotocol environments, file systems can be accessed by UNIXand Windows users. Some of the methodologies that enable this tobeachieved are:

Active Directory (using Microsoft Management Console snap-ins)

A Data Movers local user and group files

Network Information Service (NIS)

ACL= Access Control Lists

ACE= Access Control Entry

In multiprotocol environments, file systems can be accessed by UNIX and Windows users. File accessis determined by the permissions on the file or directory, the UNIX permissions, Windows access

control lists (ACLs), or both permissions and ACLs. Therefore, if a user has a UNIX and Windows

user accounts, you should choose a mapping method that allows you to indicate that the two accounts

represent the same user. Some of the methodologies that enable this to be achieved are:

Active Directory (using Microsoft Management Console snap-ins)

A Data Movers local user and group files

Network Information Service (NIS)

If a user in a multiprotocol environment only uses a single logon ( through Windows or UNIX), then it

is acceptable to use Usermapper. If a user has only one account, mapping to an equivalent identity in

the other environment is not necessary.


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Configuration/Installation

Secondary Server

Data Mover

UsermapperResolver

Example:

New User Requests Resource(New mapping required)

(1) Resolver queries

First server configured

Usermapper DB

(3)New Mapping

Request

(2) Mapping is not in DB

Primary Server

Usermapper DB

(4) Adds a new entry from specified

UID/GID range

(6)New Entry

(5) Notifies all other Secondary Servers that

they should initiate a cache update request

(8) Replies to the DataMover's request with the

UID/GID mapping

(7) Updates cache with new mapping

Usermapper DB

DART

v5.2Pre - DART

v5.2

Usermapper - Pre & Post DART v5.2

This slide illustrates the steps to grant access.

Step 1: A client request is received at a Data Mover, with the resolver stub running, without a validUID/ID. The resolver then contacts the first usermapper server configured in the configuration file

with a request for a UID/GID

Step 2 and 3: A secondary server is contacted due to its configuration priority over the primary server.If this secondary server does not have a listing for the particular user making the request in its cache, arequest is made to the primary server for a UID / GID new mapping.

Step 4 and 5: When the primary server receives a request for a new mapping, an entry from thespecified UID/GID range is added to the database and a notification is issued to all secondary serversthat their cache entries must be updated.

Step 6 and 7: The secondary server making the request for the new mapping updates its cache withnew information from the primary server upon the receipt of the update notification.

Step 8: The secondary server that received the initial request now responds back to the requesting DataMover with the new mapping information and the user is granted access (or denied access) to therequested resource.

Note:

DART v 5.2 introduces a fundamental upgrade to the usermapper process. Each Data Mover nowmaintains its own usermapper data base of user mappings. This upgrade assists with Data Moverfailover connectivity continuance and access is unaffected by possible Control Station failure.


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Virtual Data Movers

y Virtual Data Movers on Single Physical Data Movers

Ability to create multiple virtual CIFS servers on each logical DataMover

Consolidation of multiple server file serving functionality onto singleData Movers as each virtual Data Mover can maintain isolated CIFSservers with their own root filesystem environment

Allows whole Virtual Data Mover environments to be loaded,unloaded, or even replicated between physical Data Movers for easein Windows environmental management

Currently, in pre DART v5.2, a Data Mover supported one NFS server and multiple CIFS servers, where each

server has the same view of all the resources. The CIFS servers are not logically isolated and although they are

very useful in consolidating multiple servers into one data mover, they do not provide the isolation between

servers as needed in some environments such as data from disjoint departments hosted on the same data mover.

Now, VDMs support separate isolated CIFS servers, allowing you to place one or multiple CIFS servers into a

VDM, along with their file systems. The servers residing in a VDM store their dynamic configuration

information (such as local groups, shares, security credentials, and audit logs, etc.) in a configuration file system.

A VDM can then be loaded and unloaded, moved from Data Mover to Data Mover, or even replicated to a

remote Data Mover as an autonomous unit. The servers, their file systems, and all of the configuration data that

allows clients to access the file systems are available in one virtual container.

VDMs provide virtual partitioning of the physical resources and independently contain all the information

necessary to support the contained CIFS servers. Having the file systems and the configuration information

contained in a VDM does the following:

1. Enables administrators to separate CIFS servers and give them access to specified shares;

2. Allows replication of the CIFS environment from primary to secondary without impacting server

access,

3. Enables administrators to easily move CIFS servers from one physical Data Mover to another.

A VDM can contain one or more CIFS servers. The only requirement is that you have at least one interface

available for each CIFS server you create. The CIFS servers in each VDM have access only to the file systems

mounted to that VDM, and therefore can only create shares on those file systems mounted to the VDM. This

allows a user to administratively partition or group their file systems and CIFS servers.


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Additional Tools: MMC Snap-ins

y UNIX User Management

Active Directory migration tool

MMC plug-in extension for Active

Directory uses and computers

Celerra Management tool snap-in

(MMC Console)

y Virus Checker Management

Celerra Management tool:

(MMC Console)

y Home Directory snap-in Allows multiple points of entry to a single share

y Data Mover security snap-in

Manage user rights and auditing

Celerra offers a number of Windows management tools with the Windows look and feel. For example, Celerra shares

and quotas can be managed by the standard Microsoft Management Console (MMC).

The tools include:

y The Celerra Management Tool (MMC Console): Snap-in extension for Dart Virus Checker Management whichmanages parameters for the DART Virus Checker.

y The Active Directory (AD) Migration tool: Migrates the Windows/UNIX user and group mappings to Active

Directory. The matching users/groups are displayed in a property page with a separate sheet for users and groups. The

administrator selects the users/groups that should be migrated and de-selects those that should not be migrated or

should be removed from Active Directory.

y The Microsoft Management Console (MMC): Snap-in extension for AD users and computers. This adds a property

page to the users property sheet to specify UID (user ID) /GID (group ID)/Comment and adds a property page to the

group property sheet to specify GID/Comment. You can only manage users and a group of the local tree.

y The Celerra Management Tool (MMC Console): Snap-in extension for Dart UNIX User Management displays

Windows users/groups which are mapped to UNIX attributes. It also displays all domains that are known to the local

domain (Local Tree, Trusted domains).

y The Home Directories capability in the Celerra allows a customer to set up multiple points of entry to a singleShare/Export so as to avoid sharing out many hundreds of points of entry to a filesystem for each individual user for

storing their Home Directories. The MMC Snap-in provides a simple and familiar management interface for Windows

administrators for this capability.

y The Data Mover Security Settings Snap-in provides a standard Windows interface for managing user rights

assignments, as well as the settings for which statistics Celerra should audit, based on the NT V4 style auditing

policies.


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Celerra Family Software

y Describe some network high availability features

incorporated into the EMC NAS solution

Celerra family high availability features are reviewed in this section.


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NS Series Networking

y Network interfaces

Ethernet

Gigabit Ethernet

y Network protocols

TCP/IP, UDP/IP

CIFS, NFS V2, V3 and V4

FTP, TFTP, and SNMP

NDMP V2, V3, and V4

NTP, SNTP

iSCSI target

y Feature support Link aggregation

FailSafe Networking

Ethernet Trunking

Virtual LAN

Trunking

SNMP

TCP

NDMPCIFS

FTP

iSCSI

NFS

VLAN

GigabitEthernet

FSNEthernet

The NS Series implements industry-standard networking protocols:

y The network ports supported by the NS700, NS704, NS700G, and NS704G consist of 10/100/1000

Ethernet (Copper) and Optical Gigabit Ethernet. All other NS Series platforms support Copper

10/100/1000 Ethernet only.

yNetwork protocols supported include Transmission Control Protocol over Internet Protocol

(TCP/IP) and User Datagram Protocol over IP (UDP/IP).

y File-sharing protocols are CIFS (Common Internet File System), used by Windows; and NFS

(Network File System) V2, V3, and V4, used by UNIX and Linux.

y File transfers are supported with the FTP and TFTP protocols. NDMP V2, V3, and V4 are

supported for LAN-free backups.

yNetwork management can be accomplished with Simple Network Management Protocol (SNMP).

yNTP and SNTP protocols allow Data Movers to synchronize with a known time source. SNTP is

more appropriate for LAN environments.y The NS Series supports iSCSI Target for block access.

y VLAN Tagging allows a single Gigabit port to service multiple logical LANs (virtual LANs).

y FailSafe Networking extends the failover functionality to networking ports.


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Network FailSafe Device

y Network outages, due to environmental failure, are more

common than Data Mover failuresy Network FailSafe Device

DART OS mechanism to minimize data access disruption due tothese failures

Logical device is created using physical ports or other logical portscombined together to create redundant groups of ports

Logically grouped Data Mover network ports monitor network trafficon the ports

Active FailSafe Device port senses traffic disruptionStandby (non-active) port assumes the IP Address and Media

Access Control address in a very short space of time, thus reducingdata access disruption

Having discussed the maintenance of data access via redundant Data Movers, we now discuss the same conceptutilizing network port mechanisms. First lets look at the Network Failsafe device.

Network outages due to environmental failures are more common than Data Mover failures.

To minimize data access disruption due to these failures, the DART OS has a mechanism that is environmentagnostic, the Network FailSafe Device.

This is a mechanism by which the Network ports of a Data Mover may be logically grouped together into apartnership that monitor network traffic on the ports. If the currently active port senses a disruption of traffic, thestandby (non-active) port assumes the active role in a very short space of time, thus reducing data accessdisruption.

The way this works is a logical device is created, using physical ports or other logical ports, combined togetherto create redundant groups of ports.

In normal operation, the active port carries all network traffic. The standby (nonactive port) remains passive untila failure is detected. Once a failure has been detected by the FailSafe Device, this port assumes the networkidentity of the active port, including IP Address and Media Access Control address.

Having assumed the failed port identity, the standby port now continues the network traffic. Network disruption

due to this change over is minimal and may only be noticed in a high transaction oriented NAS implementationor in CIFS environments due to the connection-oriented nature of the protocol.

There are several benefits achieved by configuring the network FailSafe device: 1. Configuration is handledtransparently to client access; 2. the ports that make up the FailSafe device need not be of the same type; 3.Rapid recovery from a detected failure; 4. can be combined with logical Aggregated Port devices to provideeven higher levels of redundancy.

Although the ports that make up the FailSafe device need not be of the same type, care must be taken to ensurethat once failover has occurred, that client expected response times remain relatively the same and data accesspaths are maintained.


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Link Aggregation - High Availability

y Link aggregation

Combining of two or more data

channels into a single data channelfor high availability

Two Methods: IEEE 802.3ad LACP& CISCO FastEtherChannel

y IEEE 802.3ad LACP

Combining links for improvedavailability

If one port fails, other ports takeover

Industry standard IEEE 802.3ad

Combines 212 Ethernet ports intoa single virtual link

Deterministic behavior

Does not increase single clientthroughput

LINK

IndustryStandardSwitchCelerra

Having discussed the network FailSafe device, the next methodologies we look at are the two Link

Aggregation methodologies. Link aggregation is the combining of two or more data channels into a

single data channel. There are two methodologies that are supported by EMC NAS devices. They are

IEEE 802.3ad Link Aggregation Control Protocol and CISCO FastEtherChannel using PortAggregation Protocol (PAgP).

The purpose for combining data channels in the EMC implementation is to achieve redundancy and

fault tolerance of network connectivity. It is commonly assumed that link aggregation provides a single

client with a data channel bandwidth equal to the sum of the bandwidth of individual member

channels. This is not, in fact, the case due to the methodology of channel utilization and, it may only be

achieved with very special considerations to the client environment. The overall channel bandwidth is

increased, but the client only receives, under normal working conditions, the bandwidth equal to one of

the component channels.

To implement Link Aggregation, the network switches must support the IEEE 802.3ad standard. It is a

technique for combining several links together to enhance availability of network access and applies to

a single Data Mover and not across Data Movers. The current implementation focuses on availability,

therefore check the NAS support matrix. Only full duplex operation is currently supported. Always

check the NAS Interoperability Matrix for supported features at the following:

http://www.emc.com/horizontal/interoperability


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Channel

CISCO Switch

Celerra

Link Aggregation - High Availability (Cont.)

yCISCO EtherChannel

Port grouping for improvedavailability

Combines 2,4, or 8Ethernet ports into a singlevirtual device

Inter-operates withtrunking-capable switches

High availability: if one portfails, other ports take over

Does not increase singleclient throughput

Ethernet Trunking (Ether Channel) increases availability. It provides statistical load sharing by

connecting different clients to different ports. It does not increase single-client throughput. Different

clients get allocated to different ports. With only one client, the client accesses Celerra via the same

port for every access. This DART OS feature interoperates EtherChannel capable Cisco switches.EtherChannel is Cisco proprietary.


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Network Redundancy - High Availability

y An example of FSN and Port aggregation co-operation

This example shows a fail-safe network device that consists of a FastEtherChannel comprising the four

ports of an Ethernet NIC and one Gigabit Ethernet port. The FastEtherChannel could be the primary

device but, per recommended practices, the ports of the Fail Safe Network (FSN) would not be marked

primary or secondary. FSN provides the ability to configure a standby network port for a primary port,and the two or more ports can be connected to different switches. The secondary port remains passive

until the primary port link status is broken, then the secondary port takes over operation.

An FSN device is a virtual device that combines 2 virtual ports. A virtual port can consist of a single

physical link or an aggregation of links (EtherChannel, LACP). The port types or number need not be

the same when creating a failsafe device group. For example, a quad Ethernet card can be first

trunked and then coupled with a single Gigabit Ethernet port. In this case, all four ports in the trunk

would need to fail before FSN would implement failover to the Gigabit port. Thus, Celerra could

tolerate four network failures before losing the connection.

Note:

An active primary port/active standby port configuration on the Data Mover is not recommended

practice.


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Celerra Family Business Continuity

y Describe EMS NAS disk based replication and recovery

solutions

Having integrated the Celerra into the environment, data replication and recovery solutions that

augment the environment are reviewed next.


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Disk-Based Replication and Recovery Solutions

NS & NSX / Symmetrix

Celerra / FC4700

SynchronousSynchronousDisasterDisasterRecoveryRecovery

SRDFSRDF

Seconds

FileFile

RestorationRestorationCelerra SnapSureCelerra SnapSure

Hours

FileFile--basedbasedReplicationReplicationTimeFinder/FSTimeFinder/FS

Celerra ReplicatorCelerra ReplicatorEMC OnCourseEMC OnCourse

Minutes

NS / CLARiiON

CelerraNS

FUNCTIONALITY

RECOVERY TIME

High-end environments require non-stop access to the information pool. From a practical perspective,not all data carries the same value. The following illustrates that EMC Celerra provides a range ofdisk-based replication tools for each recovery time requirement.

File restoration: This is the information archived to disk and typically saved to tape. Here we measurerecovery in hours. Celerra SnapSure enables local point-in-time replication for file undeletes andbackups.

File-based replication: This information is recoverable in time frames measured in minutes.Information is mirrored to disk by TimeFinder, and the copy is made accessible with TimeFinder/FS.The Celerra Replicator creates replicas of production filesystems locally or at a remote site. Recoverytime from the secondary site depends on the bandwidth of the IP connection between the two sites.EMC OnCourse provides secure, policy-based file transfers.

The Replicator feature supports data recovery for CIFS and NFS by allowing the secondaryfilesystem (SFS) to be manually switched to read/write mode after the Replicator session has been

stopped, manually or due to a destructive event. Note: There is no re-synch or failback capability.Synchronous disaster recovery: This is the information requiring disaster recovery with no loss oftransactions. This strategy allows customers to have data recovery in seconds. SRDF, in synchronousmode, facilitates real-time remote mirroring in campus environments (up to 60 km).

File restoration and file-based replication (Celerra Replicator, EMC OnCourse) are available withCelerra /CLARiiON. The entire suite of file restoration, file-based replication, and synchronousdisaster recovery are available with Celerra /Symmetrix.


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Disaster Recovery

y Describe EMC NAS disaster recovery methodology using

Celerra SRDF (Symmetrix Remote Data Facility)

Celerra disaster recovery, when integrated with the Symmetrix, utilizes a very synergistic combination

of Celerra and the Symmetrix functionality.


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2006 EMC Corporation. All rights reserved.

Celerra SRDF Disaster Recovery

y Increases data availability by combining the high availability of the Celerra family withthe Symmetrix Remote Data Facility

y Celerra synchronous disaster recovery solution Allows an administrator to configure remote standby Data Movers waiting to assume primary

roles in the event of a disaster occurring at the primary data site

SRDF allows administrator to achieve a remote synchronous copy of production filesystems at aremote location

Real-time, logically synchronized and consistent copies of selected volumes Uni-directional and bi-directional support

Resilient against drive, link, and server failures

No lost I/Os in the event of a disaster

Independent of CPU, operating system, application, or database

Simplifies disaster recovery switchover and back

CelerraCelerraUni or bi-directional

Campus (60 km) distance

Network

In the NAS environment, data availability is one of the key aspects for implementation determination. By combining thehigh availability of the Celerra family with the Symmetrix Remote Data Facility, data available increases exponentially.What the SRDF feature allows an administrator to achieve is a remote synchronous copy of production filesystems at aremote location. However, as this entails the creation of Symmetrix specific R1 and R2 data volumes, this functionality iscurrently restricted to Celerra / Symmetrix implementations only.

This feature allows an administrator to configure remote standby Data Movers waiting to assume primary roles in the eventof a disaster occurring at the primary data site. Due to data latency issues, this solution is restricted to a campus distance ofseparation between the two data sites (60 network km).

The SRDF solution for Celerra can leverage an existing SRDF transport infrastructure to support the full range of supportedSAN (storage area network) and DAS (direct-attached storage) connected general purpose server platforms. The Celerradisaster recovery solution maintains continuously available filesystems, even with an unavailable or non-functioningCelerra. Symmetrix technology connects a local and remote Celerra over a distance of up to 40 miles (66 km) via anESCON or Fiber Channel SRDF connection. After establishing the connection and properly configuring the Celerra, usersgain continued access to filesystems in the event that the local Celerra and/or the Symmetrix becomes unavailable. TheCelerra systems communicate over the network to ensure the primary and secondary Data Movers are synchronized withrespect to meta data, while the physical data is transported over the SRDF link. In order to ensure an up to date andconsistent copy of the filesystems on the remote Celerra, the synchronous mode of SRDF operation is currently the onlysupported SRDF operational mode. Implementation of Celerra disaster recovery software requires modification of thestandard Celerra configuration. SRDF has two modes of operation: active-passive and active-active. Active-passive (Uni-

directional) SRDF support means that one Celerra provides active Data Mover access while a second (remote) Celerraprovides all Data Movers as failover. Active-active (Bi-directional) SRDF support means that one Celerra can serve localneeds while reserving some of its Data Movers for recovery of a remote Celerra, which reserve some of its Data Movers forrecovery of the first Celerra . In addition, local failover Data Movers can be associated with Data Movers in the primarySymmetrix to ensure that local failover capability is initiated in the unlikely event there is a hardware related issue with aspecific Data Mover.

The mode of operation with SRDF/S is Active-Active.

y With active-active(SRDF/S only) support, one NS Series/NSX Gateway can serve local needs while reserving someof its Data Movers for recovery of a remote NS Series/NSX Gateway, which reserve some ofitsData Movers forrecovery of the first NS Series/Gateway.


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