Tài liệu Module 7: Planning Server Roles and Placement pptx

Planning Front-end/Back-end Servers 12 Planning for Servers Running Active Directory 17 Discussion: Planning Server Placement 21 Lab A: Identifying Server Roles and Placement 22 Lab

Planning Front-end/Back-end Servers 12

Planning for Servers Running Active

Directory 17

Discussion: Planning Server Placement 21

Lab A: Identifying Server Roles and

Placement 22

Lab B: Implementing Front-end Load

Balancing 29

Lab C: Implementing a Front-end Server 35

Lab D: Implementing a Public Folder

Server 39

Module 7: Planning Server Roles and Placement

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Instructor Notes

This module provides students with the knowledge required to determine how many servers their Microsoft® Exchange 2000 organization requires

After completing this module, students will be able to:

!"Plan mailbox servers and public folder servers

!"Plan connector servers

!"Plan front-end/back-end servers

!"Plan servers running the Microsoft® Active Directory™directory service

!"Identify the factors to be considered when designing server placement

Materials and Preparation

This section provides the materials and preparation tasks that you need to teach this module

Required Materials

To teach this module, you need the following materials:

!"Microsoft PowerPoint® file 1573A_07.ppt

!"The Exchange 2000 & DS Topology Calculator job aid

!"The Northwind Traders Case Study

Preparation Tasks

To prepare for this module, you should:

!"Read all of the materials for this module

!"Complete the labs and the lab discussion questions

!"Read the following white papers, located under Additional Readings on the

Student Materials compact disc:

• “E2K_FEScalability”

• “E2KBackEnd_Scalability”

• “Tuning”

• “CalcPlan”

!"Practice using the Exchange 2000 & DS Topology Calculator job aid

!"Review the Northwind Traders Case Study

The job aids are in the Exchange 2000 Design Tool located at C:\MOC\1573A\LabFiles\Exchange_2000_Design_Tool, and on the student compact disc The case studies are in the Appendices and on the student compact disc

Module Strategy

Use the following strategy to present this module:

!"Planning Mailbox Servers and Public Folder Servers Begin by making sure that the students understand the function of each type

of server Continue by discussing capacity planning guidelines for each server Next, discuss the planning considerations that are associated with mailbox servers and public folder servers Complete the module by explaining how to plan storage needs and partition databases

!"Planning Connector Servers Make sure that the students understand the function of a connector server Explain each planning consideration, and then discuss the server

specifications for Simple Mail Transfer Protocol (SMTP) connector servers

!"Planning Front-end/Back-end Servers Begin by discussing the advantages of using a front-end/back-end server topology Next, explain the server specifications for Post Office Protocol version 3 (POP3), Internet Message Access Protocol version 4 (IMAP4), and Microsoft Outlook Web Access front-end servers

!"Planning for Servers Running Active Directory Begin by making sure that the students understand how global catalog servers and domain controllers function Next, explain how to determine the number of global catalog servers that a company needs Finish this topic by explaining how to place global catalog servers and domain controllers in an Exchange 2000 organization

!"Discussion: Planning Server Placement This topic presents a scenario, and then asks the students to discuss the server placement options and design considerations that the company in the scenario should take into account when planning where to place their servers

Customization Information

This section identifies the lab setup requirements for a module and the configuration changes that occur on student computers during the labs This information is provided to assist you in replicating or customizing Microsoft Official Curriculum (MOC) courseware

Lab Setup

The following list describes the setup requirements for the labs in this module

!"For each student, a Microsoft Management Console (MMC) custom console must be created This custom console must include both the

Active Directory Users and Computers snap-in and the Exchange System

snap-in, and must be named your_firstname Console

!"For each student, a personalized user account must be created in the appropriate domain This user account must be added to the Domain Admins group, and assigned a mailbox on the server running Exchange 2000 that the student is using

!"For each student, a user profile must be created on the student’s computer that enables the student to access their mailbox by using Microsoft Outlook® 2000

!"The students sitting at the City-MBX1 computers will need the

IMAP4Stresser application that is located at c:\moc\1573a\labfiles

!"DNS is configured to have a front-end namespace for each routing group

!"The City-FE1 and City-FE2 servers in each routing group are converted to

Overview

! Introduction to Planning Server Roles and Placement

! Planning Mailbox Servers and Public Folder Servers

! Planning Connector Servers

! Planning Front-end/Back-end Servers

! Planning for Servers Running Active Directory

! Discussion: Planning Server Placement

Microsoft® Exchange 2000 organizations designed for the enterprise usually deploy several different servers Although it is possible to install the entire functionality of Exchange 2000 on a single server, it is usually better to distribute the functions among several servers Architects designing an Exchange 2000 organization need to be able to identify and plan for the deployment of each of the types of servers that a company needs

In addition to identifying server roles, the necessary planning tasks include determining the number of each type of server that a company requires, as well

as where to place each server To complete these tasks, you must understand the various roles of the different types of servers, and of the design effects

associated with their deployment

After completing this module, you will be able to:

!"Plan mailbox servers and public folder servers

!"Plan connector servers

!"Plan front-end/back-end servers

!"Plan servers running the Microsoft® Active Directory™directory service

!"Identify the factors to be considered when designing server placement

In this module, you will learn

about the Exchange 2000

server roles, and how to

plan and place servers for

an effective Exchange 2000

organization

Introduction to Planning Server Roles and Placement

User Internet Front End

Servers

Back End Servers

Mailbox Server Connector Server Internet

User

Mailbox Server

Public Folder Server

Although each server running Exchange 2000 often performs several roles in a smaller organization or in a remote office, it is often preferable to dedicate servers to perform specific roles

Distributing functions among several different servers enables you to provide faster response time and reduced downtime Distributing roles also helps prevent servers from becoming overloaded, and removes the dependencies between services

Planning server roles and placement will help you decide which hardware to purchase and will affect the performance of your messaging system It is important to have your budget settled prior to planning your server roles, because dedicating servers to specific roles may significantly increase the number of servers that you will need to purchase

Topic Objective

To outline the different types

of servers that a company

may deploy

Lead-in

There are several ways to

deploy servers running

Exchange 2000

# Planning Mailbox Servers and Public Folder Servers

Topic Objective

To outline the design

considerations that are

associated with planning

mailbox and public folder

servers

Lead-in

There are several design

considerations to take into

account when planning

mailbox and public folder

servers

Capacity Planning

Storage limits Time required to perform a backup Time required to recover from a disaster Time required to restore a single database Time required to restore a single mailbox

Capacity Planning for Mailbox Servers

Service levels Response time

Capacity Planning for Public Folder Servers

The number of users and public folders that each server can support depends primarily on the usage profile for each user

Mailbox Servers

The most important factors to consider when calculating the number of mailboxes to store on each server are: the storage limits, the time required to perform a backup, the time to recover from a disaster, the time to restore a single database, and the time to restore a single mailbox

Public Folder Servers

Service levels and response time are the primary factors to consider when determining whether to dedicate a server to public folder storage For example,

if your company builds custom applications into multiple public folder hierarchies, it is recommended that you place these hierarchies on a separate server so that people gaining access to these custom application folders do not increase the response time for people checking their mailboxes

Topic Objective

To provide capacity

planning information for

mailbox and public folder

servers

Lead-in

The number of users and

public folders that each

server can support depends

primarily on the usage

profiles for each user

Planning Considerations

What is the default storage limit on mailboxes?

What is the retention policy for deleted items?

Which protocols are enabled for mail?

How many mailboxes on each server are related to service level agreements with customers?

How many mailboxes on each server are related to service level agreements with customers?

How long will data be stored on the server?

Although Exchange 2000 does not impose a limit on the number of mailboxes

or public folders that can reside on any one server, you must consider storage limits, data storage, retention policies, protocols, and service level agreements when planning mailbox servers and public folder servers:

Default Storage Limit on Mailboxes

The default storage limit on mailboxes, combined with the number of users that you support, will help you to determine how many mailbox servers you need For example, if you have 500 users, and if you limit each user mailbox to a maximum size of 50 megabytes (MB), then you need to plan for a minimum of

25 gigabytes (GB) of mailbox space

Storing Data

You can control the amount of data that is stored on a server by using tools such

as the Mailbox Cleanup Agent to search databases and to delete old messages You can also configure Post Office Protocol version 3 (POP3) and Internet Message Access Protocol version 4 (IMAP4) client applications to move retrieved messages to their local client The less data you store on your server, the less storage space you need

Retention Policy

If you want to archive or to retain deleted items, you need to develop a retention policy that accounts for the additional space that you will require Consider the average size of the messages that your users receive, as well as the average number of messages that users delete per day

To outline the planning

considerations that are

related to mailbox and

public folder server roles

and placement

Lead-in

There are several

considerations to take into

account when planning

mailbox and public folder

servers

Service Level Agreements

You must consider the number of mailboxes on each server that are related to service level agreements If large mailbox stores exist, consider splitting each of them into several smaller ones In the past, service level agreements often required the deployment of multiple servers to ensure recovery within the time constraints of the service level agreement Creating multiple storage groups and databases enables you to consolidate these servers into one larger server that has multiple mailbox stores and databases

Planning Storage Needs

Servers

First Storage Group Default Mailbox Store Executives

Second Storage Group News Store

Third Storage Group Public Folders Server 1

You can use storage groups to store data on your mailbox servers and on your public folder servers

Microsoft Exchange 2000 Enterprise Server supports a maximum of four storage groups with a maximum of five databases in each storage group Each mailbox and each public folder store is a member of a storage group All mailboxes and all public folder stores in each storage group share a single set of transaction log files You can place one or more storage groups on each server The following table outlines a possible Exchange 2000 store configuration

Storage Group Database

mailbox store

Creating Multiple Storage Groups

If you plan to create multiple storage groups on one server, make sure that you can place the transaction logs and the database onto separate disk spindles The primary reasons for separating the transaction logs from the database are to increase performance while logging transactions, and to take advantage of sequential writes Storing transaction log files on their own dedicated disk spindle also aids in the database recovery process If your transaction log files are stored on their own dedicated disk spindle, and if you have circular logging disabled, then if a database associated with those transaction log files becomes damaged, it is possible to recover all data that was entered up to the time when the database became damaged

Topic Objective

To outline the storage

requirements that are

associated with mailbox

servers and public folder

servers

Lead-in

You can use storage groups

to store the data on your

mailbox servers and on your

public folder servers

Delivery Tip

Have the students discuss

alternative storage group

options to those outlined in

the table on this page

Partitioning Databases

! Makes database management easier and more logical

! Reduces the effects of a malfunctioning database

Storage Group 2 Storage Group 1

Mailbox Server

If you do not have enough disk drives available, you can store all of your databases on the same partition However, if you do have enough disk space to allow for placing separate databases on separate partitions, it is recommended that you do so

Placing database files from different storage groups on separate partitions:

!"Makes database management easier and more logical

!"Reduces the effects of a malfunctioning database If the drive array that houses one storage group of databases goes offline, the failure will not affect databases in any other storage group

If you distribute databases from multiple storage groups over a single drive array, and that drive array goes offline, then all databases associated with those storage groups will go offline temporarily, even if some of those databases are located on other arrays The damaged database will be marked

as down, and the working databases will remount Ordinarily, this type of outage will only last for a few minutes At the end of that period, Messaging Application Programming Interface (MAPI) clients such as Outlook will recover their connections

Topic Objective

To explain how to partition

databases

Lead-in

There are several reasons

for storing database files

from separate storage

groups on separate

partitions

# Planning Connector Servers

! Planning Considerations

! Server Specifications for SMTP Connector Servers

There are several planning considerations, as well as several server specifications, that you must take into account when deciding whether or not to dedicate connector servers

Topic Objective

To outline the design

considerations that are

associated with using

specifications, that you must

take into account when

deciding whether or not to

dedicate connector servers

Planning Considerations

Frequency of Connector User

Routing Topology

Internet Connectivity

Number of Messages Sent between Routing Groups

Connector servers route mail messages and public folder information Consider each of the following factors before dedicating a connector server to a routing group:

!"Frequency of connector use

In addition to how many routing groups are being connected, consider how frequently the connector will be used How frequently a connector will be used is determined largely by its cost For example, if you have an X.400 connector that connects a routing group to a foreign system with a cost

of 100, do not dedicate a bridgehead server to that routing group

!"Routing topology

If you use a hub-and-spoke topology, you must dedicate enough bridgehead servers to accommodate the message flow between all of your routing groups Link cost is not an issue in this case, because all messages must travel through the hub

If you use a full-mesh topology, you should not need as many connector servers as you would with a hub-and-spoke topology, because in a full-mesh topology all messages are routed directly from the originating routing group

to the destination routing group

!"Internet connectivity Many companies prefer to dedicate a connector server to Internet connectivity to ensure that Internet message activity is never slowed down

or interrupted In addition, you can use virus scanners to filter messages and information that are being routed through bridgehead servers

!"Number of messages sent between routing groups

If the majority of internal messages are sent between users in different routing groups, dedicate a bridgehead server to each routing group in which you expect heavy mail usage If most messages will be sent between users

in the same routing group, you probably do not need to dedicate a specific bridgehead server for that routing group

Topic Objective

To outline the planning

considerations that are

related to connector servers

Lead-in

There are several factors

that you must consider

before dedicating a

connector server to a

routing group

Server Specifications for SMTP Connector Servers

Processor

Disk Space

Memory

Network Connectivity

!"Disk space Requires a large number of disk resources; at least seven disk writes are required for each message that is queued The drive that contains the queue on high-end servers should be configured as Redundant Array of Independent Disks (RAID) 0+1 and should have multiple disk spindles that make use of a write-caching array controller

!"Network connectivity Two-processor servers require a single 100 per-second (Mbps) connection Four-processor servers should be fitted either with two 100-Mbps connections or with a single Gigabit Ethernet connection

megabit-For more detailed information about SMTP connector server scalability,

see Microsoft Exchange 2000 Front-End Server and SMTP Gateway Hardware

Scalability Guide under Additional Readings on the Student Materials

maintenance costs by using

the same hardware platform

for all of your connector

servers

Note

# Planning Front-end/Back-end Servers

! Advantages of Using a Front-end/Back-end Topology

! Server Specifications

Consider planning a front-end/back-end server topology if your company deploys multiple servers running Exchange 2000, if those servers use Outlook Web Access, POP3, or IMAP4, and if your company provides Outlook Web Access, POP3, or IMAP4 access to their employees over the Internet

Topic Objective

To discuss the planning

issues associated with using

front-end/back-end servers

Lead-in

Using a front-end/back-end

server topology is a good

idea for companies that use

Outlook Web Access,

POP3, and IMAP4 in a

multiple server environment

Advantages of Using a Front-end/Back-end Topology

Front-end Exchange 2000 Servers Client

Implementing a front-end/back-end server topology provides:

!"A single namespace The primary advantage of a front-end/back-end server architecture is that it provides a single consistent namespace for each user You can define a single namespace for users that enables them to gain access to their mailboxes With a single namespace, users can use the same Uniform Resource Locator (URL) or POP3 and IMAP4 client configuration, even when servers are added and removed, or when mailboxes are moved from one server to another server In addition, creating a single namespace ensures that Outlook Web Access, POP3, and IMAP4 access remains scalable as the Exchange 2000 organization grows

!"Offload processing Front-end servers can handle all encryption and decryption processing This improves performance by removing processing tasks from back-end servers while still allowing the data to be encrypted between the client computer and the Exchange 2000 servers In addition, you can offload Hypertext Transfer Protocol (HTTP) compression to the front-end servers, which enables client computers in low-bandwidth environments to retrieve data much more quickly, and improves network availability

There are several

advantages associated with

deploying a

front-end/back-end server topology

!"Load balancing If you implement the Windows 2000 Network Load Balancing Service on each of your front-end servers, you can load balance the processing of your front-end servers This service allows you to group as many as 32 servers in a single namespace

!"Strengthened security You can position each front-end server as the single point of access either on or behind an Internet firewall that is configured to allow traffic from the Internet to the front-end server only Because the front-end server does not store user information, it provides an additional layer of security Also, you can configure the front-end server to

authenticate requests before proxying them, which protects the back-end servers from security breaches

Server Specifications

POP3 Front-end Server

IMAP4 Front-end Server

Outlook Web Access Front-end Server

! Processor

! Memory

! Disk Space

! Network Connectivity

Front-end server configuration depends on several factors, including the number of users per back-end server, the protocols used, and the expected rate

of use As a general rule, one front-end server for every four back-end servers is adequate You should also plan to include at least two front-end servers in your design for purposes of redundancy and load balancing Consider the following hardware recommendations for POP3, IMAP4 and Outlook Web Access front-end servers

POP3 Front-end Server

!"Processor POP3 scales well to 2-processor servers, but is not recommended for 4-processor servers

!"Memory 256 MB of RAM is sufficient for nearly all applications

!"Disk space POP3 uses virtually no disk resources, unless the server is paging or POP3 protocol logging is turned on

!"Network connectivity If run on a high-end, 800-MHz, 2-processor server, POP3 requires either a second 100-Mbps network interface card (NIC) or a Gigabit Ethernet connection

!"It is recommended that you use a ratio of one front-end server to four end servers

back-!"If all connections will be performed over Secure Sockets Layer (SSL), then the processor capacity of a POP3 front-end server should be doubled

Topic Objective

To discuss the server

specifications that are

associated with front-end

and back-end servers

Lead-in

As a general rule, one

front-end server for every four

back-end servers is

adequate

IMAP4 Front-end Server

!"Processor IMAP4 scales well to 2-processor servers

!"Memory IMAP4 requires a minimum of 256 MB of RAM However, if you are using a front-end server that services more than five back-end servers, you should use at least 512 MB of RAM

!"Disk space IMAP4 uses virtually no disk resources, unless the front-end server is paging, or unless IMAP4 protocol logging is turned on

!"Network connectivity A single 100-Mbps full duplex network connection is sufficient for most front-end applications Depending on the type of users that you plan to service and the number of back-end servers to be serviced,

it may be necessary to add an additional 100-Mbps full duplex NIC, or to move to a gigabit-based network

!"As a general rule, use a ratio of one IMAP4 front-end server to eight end servers

back-!"SSL connections generate a 50 percent increase in CPU activity, and require

an additional 10 percent of physical memory

Outlook Web Access Front-end Server

!"Processor Outlook Web Access scales well to 4-processor servers

!"Memory An Outlook Web Access front-end server uses approximately 30

KB of RAM per active connection

!"Disk space Outlook Web Access uses virtually no disk resources, unless the front-end server is paging, or unless HTTP Distributed Authoring and Versioning (HTTP-DAV) protocol logging is turned on

!"Network connectivity If Outlook Web Access is servicing over 5,000 connections, then it requires a second 100-Mbps NIC

!"As a general rule, use a ratio of one front-end server to four back-end servers

!"Outlook Web Access SSL connections require up to 3 times more processing power and 60 percent more memory on their front-end server

For more detailed information about front-end server scalability, see

Microsoft Exchange 2000 Front-End Server and SMTP Gateway Hardware

Scalability Guide under Additional Readings on the Web page on the Student

Materials compact disc

Note

# Planning for Servers Running Active Directory

! Placing Domain Controllers

! Determining the Number of Global Catalog Servers

! Placing Global Catalog Servers

Identifying the Active Directory domain controller and global catalog server requirements for Exchange 2000 requires an understanding of how client applications and servers gain access to information stored in the Active Directory database

If at all possible, it is a good

idea to plan your Active

Directory servers before you

install Exchange 2000

Placing Domain Controllers

Domain Controller

Exchange 2000

Exchange 2000 Exchange 2000

Domain Controller

configuration naming context and the schema naming context for the entire forest Architects need to consider how the domain controllers will be placed in

an Exchange 2000 organization

In a two-tier domain topology, where servers running Exchange 2000 are located in one domain and the users whose mailboxes are located on those servers are located in the other domains, you can improve performance by locating a domain controller for the root domain in each of the child domains’ physical locations or sites This way, the ticket-referral process is completed locally, and only the session ticket is presented across the wide area network (WAN)

authenticate the credentials

of users who are attempting

to gain access to their

mailboxes There must be at

least one domain controller

in each domain

Determining the Number of Global Catalog Servers

Northwind Traders

General directory searches by users and applications User principle name logon requests Universal group membership enumeration

Queries from a server running Exchange 2000

Calculations

Assessment Access Hardware Assessment

Access Hardware

Global Catalog Servers

Like the sizing and placement of domain controllers, the sizing and placement

of global catalog server depends on several factors in addition to the requirements of Exchange 2000 In an Exchange 2000 environment, the global catalog server is generally accessed for:

!"General directory searches by users and applications An example of a general directory search is a user looking up an address within the Global Address List

!"User principle name logon requests from a domain controller

!"Universal group membership enumeration

!"Queries from a server running Exchange 2000

Because the domain partition is not replicated between domains, the global catalog provides visibility to objects across domains In addition to storing and replicating a complete set of all objects in the directory for reference by its own host domain, a global catalog server stores and replicates a partial replica of the domain directory partition for reference by all other domains in the forest

Queries to the Global Catalog Server

By default, the partial set of attributes stored in the global catalog includes those attributes most frequently used by Exchange 2000 users Most Active Directory queries from Exchange 2000 messaging clients are made to the global catalog server Servers running Exchange 2000 also query the global catalog server for recipient information

For example, when Outlook 2000 users look up addresses of other users in their organization, the information comes from the global address list (GAL) The GAL is built by Exchange 2000, which queries the global catalog server When

a client computer requests specific user information, the query is sent to a specific global catalog server

Topic Objective

To outline the process of

calculating the number of

global catalog servers that

are required for a specific

Exchange 2000

organization

Lead-in

It is important to plan for an

adequate number of global

catalog servers, because

the partial set of attributes

that are stored in the global

catalog includes the

attributes most frequently

used by Exchange 2000

users

Placing Global Catalog Servers

Northwind Traders

90,000 users

5 Active Directory sites

9 servers running Exchange 2000

in each site

25,000 Users

20,000 Users

25,000 Users

5,000 Users

20,000 Users

One GC per site

Additional GC per 11,000 users

Additional GC per 11,000 users

The location of global catalog servers is important to your Exchange 2000 organization, because client computer and server performance depends on the immediate availability of fast, reliable Active Directory services

You should ensure that Active Directory sites that contain servers running Exchange 2000 have adequate global catalog services for the number of users that are supported by those servers If Outlook 2000 is your primary messaging client, then you can increase performance by placing global catalog servers onto the same network segment as your users and as your servers running

Exchange 2000 This is because Outlook 2000 clients use a referral process, and they will communicate directly with the global catalog servers to which their servers running Exchange 2000 refer them

Topic Objective

To explain the placement of

global catalog servers

Lead-in

Exchange 2000 clients

depend on global catalog

servers to provide fast and

reliable access to Active

Directory services