Designing Exchange Infrastructure

After Active Directory and the physical OS has been chosen and deployed, the Exchange infrastructure can be set up and optimized for the specific needs of the organization. With these needs in mind, there are several things that can be done to optimize an Exchange Server 2003 setup, as detailed in the following sections.

Exchange Version and Org Name

When installing Exchange, the choice of Exchange version needs to be made. As with Windows Server 2003, there are two versions of Exchange, Standard and Enterprise. The Standard version enables all Exchange Server 2003 functionality except the following:

• Multiple databases

• Databases larger than 16GB

• Clustering support

• X.400 Connectors

In smaller organizations, nearly all implementations of Exchange require only the Standard version; the advanced feature set of the Enterprise Edition is geared toward larger deployments. The critical factor that pushes the midsize-to-large organizations to the Enterprise version, however, is the 16GB database limit. Some organizations require large mailbox sizes and could potentially require multiple databases larger than 16GB. Because this functionality is available only with the Enterprise version of the software, it must be installed.

CAUTION

Because the standard version of Exchange does not support databases larger than 16GB, keep track of the size of the private database store, ensuring that it stays well below the 16GB limit. The database will shut down if it reaches this limit.

When installing the first Exchange Server 2003 system, the setup program prompts for the creation of the Exchange Organization. The information entered in the Exchange Organization is fairly trivial, because end-users do not access this information. However, the Exchange Organization is unique across the forest and should reflect the name of the organization that will use the Exchange Server 2003 implementation.

Administrative Group and Routing Group Structure

Exchange Server 2003 continues with the Exchange 2000 concept of separating the administration of servers with the physical location of those servers. In other words, Exchange servers could exist in multiple sites but be administered by the same group. The administration of Exchange servers is subsequently facilitated through the creation of administrative groups, and the physical server routing facility is facilitated through routing groups.

In a nutshell , administrative groups in Exchange Server 2003 should be established to designate administrative boundaries for Exchange components . In other words, if the entire organization is centrally administered, there should be only a single admin group for the entire organization. If there is a separate admin group ”for servers in Europe, for example ”multiple admin groups can be created to provide eased delegation of administration.

Routing groups, on the other hand, are used to optimize replication between "islands" of high connectivity, similar to the concept of Active Directory and Exchange 5.5 sites. Servers within the same routing group communicate with each other faster and more often, and Exchange systems in remote routing groups can be configured to replicate information on a scheduled basis.

Public Folder Structure and Replication

Public folders in Exchange have a somewhat mixed relationship with administrators and users. Many organizations widely use the group calendaring and posting features of public folders, but others maintain a public folder database with little or no data in it.

Public folder architecture for small organizations is usually quite simple; because there is normally only one Exchange server, only one public folder instance is possible. If there is more than one server and fast access to public folder information is required, it may be necessary to create a second public folder instance.

Midsize-to-large organizations, on the other hand, can take advantage of the ability to have multiple read/write copies of public folder trees by deploying public folder instances in various servers across the organization. This ensures fast public folder access for users.

Exchange Databases and Storage Groups

As previously mentioned, the Enterprise version of Exchange enables the concept of multiple databases, up to a maximum of 20. This enables a greater amount of design freedom and gives administrators more flexibility. A maximum of four production storage groups can be created, and each storage group can contain up to five databases.

NOTE

Exchange Server 2003 introduces a concept called a recovery storage group, which enables the restoration of mailbox data to a completely separate storage group from the regular mail data. An Exchange Recovery storage group can be installed as a fifth storage group on the Enterprise version of Exchange, but it also can be used on the Standard version.

Exchange Recovery Options

Deploying Exchange requires considerable thought about backup and recovery solutions. Because Exchange is a live, active database, special considerations need to be taken into account when designing the backup strategy for email.

Microsoft designed Exchange Server 2003 to use the new backup APIs from Windows Server 2003. These APIs support the Volume Shadow Copy service, which enables Exchange databases to be backed up through creation of a "shadow copy" of the entire disk at the beginning of the backup. The shadow copy is then used for the backup, so that the production disk is not affected.

NOTE

The Windows Server 2003 backup utility can be used to back up Exchange using the traditional online backup approach. Volume Shadow Copy requires a third-party solution that has been written to support the new Windows Server 2003 backup and restore APIs.

Exchange Server 2003 also includes support for the concept of a recovery storage group, which is an additional storage group (available with either Standard or Enterprise Exchange) and which can be used on a running server to restore databases and mailboxes "on the fly." This streamlines the mailbox recovery process, because restore servers are no longer a necessity. For more information on backup and recovery options, see Chapter 31, "Backing Up the Exchange Server 2003 Environment."

Exchange Antivirus and Antispam Design

Viruses are a major problem for all organizations today. Email is especially vulnerable, because it is typically unauthenticated and insecure . Consequently, design of an Exchange implementation should include consideration for antivirus options.

Exchange Server 2003 improves upon the Virus Scanning Application Programming Interface (VSAPI) that was introduced in Exchange 2000. The enhanced VSAPI 2.5 engine enables quarantine of email messages, as opposed to simply attachments, and enables virus scanning on gateway servers. Third-party virus products can be written to tie directly into the new VSAPI and use its functionality.

Spam, unsolicited email, has become another major headache for most organizations. In response to this, Exchange Server 2003 has some built-in antispam functionality that enables email messages to contain a spam rating. This helps determine which emails are legitimate , and can be used by third-party antispam products as well.

Exchange Monitoring Solution

Email services are required in many organizations. The expectations of uptime and reliability are increasing, and end-users are beginning to expect email to be as available as phone service. Subsequently, the ability to monitor Exchange events, alerts, and performance data is optimal.

Exchange Server 2003 is a complex organism with multiple components, each busy processing tasks , writing to event logs, and running optimization routines. There are several methods of monitoring Exchange, the most optimal being Microsoft Operations Manager (MOM). MOM is essentially a monitoring, alerting, and reporting product that gathers event information and performance data, and generates reports about Microsoft servers. An Exchange-specific management pack for MOM contains hundreds of pre-packaged counters and events for Exchange Server 2003. Use of the management pack is ideal in midsize and larger environments to proactively monitor Exchange.

Although close monitoring of multiple Exchange servers is best supported through the use of MOM, this may not be the most ideal approach for smaller organizations because MOM is geared toward medium and large organizations. Exchange monitoring for small organizations can be accomplished through old-fashioned approaches, such as manual reviews of event log information, performance counters using perfmon , and simple SNMP utilities to monitor uptime, which is the approach taken by Company123.

Small Organization Exchange Infrastructure Design Decisions

In small organizations such as CompanyABC, it is typical for a single group (or single individual) to administer the entire organization, so a single administrative group should suffice. In addition, there may be only one site (or a small number of sites) and Exchange Server 2003 can be configured with a single routing group for each site. Because of its size, Company123 used a single routing group and a single administration group, as illustrated in Figure 5.11.

Figure 5.11. Routing group and admin group design for a small organization.

The Exchange infrastructure was deployed at Company123 with Exchange Standard Edition on its single server. The Exchange organization was named Company123 for simplicity.

Because Company123 was using the Standard version of Exchange Server 2003, it did not require additional thought into database or storage group design. Following this logic, it deployed a single private information store, a single public information store, and a single storage group.

Midsize Organization Exchange Infrastructure Design Decisions

Administration within OrganizationY is centralized, and required the creation of a single admin group for the Exchange Organization. The Exchange organization was named OrganizationY and the routing group structure was divided into separate routing groups for Manchester and Los Angeles, as illustrated in Figure 5.12.

Figure 5.12. Routing group and admin group design for a mid-size organization.

Each Exchange Server in the organization used the Enterprise version of Exchange, because support for large and multiple databases was required. A third-party backup and antivirus solution were chosen to protect the mail data. The Exchange servers were each configured with three private store databases for mailboxes, and one public folder store, as illustrated in Figure 5.12. Users were distributed across the databases by practice group ”with management in one database and marketing in another, for example. This helped OrganizationY shorten recovery time for certain groups while also enabling separate mailbox limits and database options.

Microsoft Operations Manager was deployed in the Manchester location to monitor all AD and Exchange servers and provide for proactive systems management.

Large Organization Exchange Infrastructure Design Decisions

CompanyABC was divided into two separate IT Teams. One IT team managed the parent company, which included the Minneapolis, San Francisco, Moscow, and Tokyo offices. The second IT team managed the company that had been acquired , which included the Dallas, New York, Paris, and Singapore offices. Consequently, two administrative groups were created and a total of eight routing groups were created, as illustrated in Figure 5.13. The Exchange organization was named CompanyABC .

Figure 5.13. Routing group and admin group design for a large organization.

All servers across the entire organization were installed with the Enterprise version of Exchange to enable large databases, as illustrated in Figure 5.13. The user base was distributed across the databases alphabetically to ease the administration of the mailboxes. Each site contained a local copy of the public folder tree to ensure quick response time. Finally, third-party antispam, antivirus, and backup solutions were put in place to protect Exchange.

Microsoft Operations Manager was deployed with the Exchange Server 2003 Management Pack and configured to monitor all components of Active Directory and Exchange Server 2003.