How to Perform an Exchange Migration

In this phase, existing mail accounts and messagesor modify existing migration scripts. All scripts for
are migrated from the existing messagingmanaging batch processes must be completed and
environment to the Microsoft Exchange 2003tested prior to
environment. Your migration strategy must be------------------Choosing Full or Limited Migration
executed in a manner that is transparent and thatAccounts to migrate can be defined based on
has the minimum possible impact on your currentbusiness rules (for example, all mail accounts in good
e-mail users.To accomplish these goals, an effectivestanding or priority accounts requiring early access to
migration strategy and appropriate migration toolsfeatures not offered in the exiting mail system).If
must be designed and implemented. They mustyou are not going to migrate the entire population at
address all aspects of system migration, includingone time, there are certain considerations you need
networking, external interfaces, accountto plan for. For limited migration, you must configure
synchronization, management systems, and parallelthe Microsoft Exchange 2003 system for POP proxy
operations.This chapter contains the followingin order to retrieve mail from the legacy system for
sections:Developing a Migration StrategyPreparing theunmigrated accounts and mailboxes. The architecture
Migration PlanUsing Migration UtilitiesTips for amust also account for SMTP relay during Proxy mode
Successful MigrationRefer to the Microsoft Exchangein order to deliver appropriate mail to the legacy
2003 Migration Guide for complete information onsystem as well as to Microsoft Exchange 2003.The
migration.Developing a Migration Strategymethod of migrating account data must be identified
The typical site where Microsoft Exchange 2003 isand tested. Before the limited account migration can
installed has an existing mail system that providesoccur, a back-out plan, migration quality assurance,
messaging services to its users. Migration is the actand certification of migration must be resolved and
of moving or copying the data for all users from thevalidated by testing.In many instances, new
legacy (existing) system to the Microsoft Exchangesubscribers to mail service at the customer site are
2003 system. Migration is performed so that alladded to the Microsoft Exchange 2003 system
customers can be serviced by the Microsoftbefore migrated accounts from the legacy system.
Exchange 2003 system, not simply those newThe benefits of handling new registrations in
subscribers following the installation of MicrosoftMicrosoft Exchange 2003 are that you may be able
Exchange 2003.Migration is the most complex facetto:Offer differentiated service immediately.Introduce
of any deployment project. Even though thisMicrosoft Exchange 2003 at a measured pace.Ensure
document provides a framework to follow forthat no more users are added to an obsolete
migration, no two migrations are exactly alike, due tosystem.Resuming Service
the differences in each site's legacy mail system andOnce migration is completed, accounts are
its integrated systems and procedures. A successfulautomatically switched from Proxy mode to active
migration depends upon accurately identifying allstatus. Users regain access to their mailboxes and all
unique aspects of the system that are to bemessages that were deferred during migration are
duplicated in Microsoft Exchange and then duplicatingdelivered to their intended recipients. In addition, you
these conditions through development and testingmust move operations entirely to the Microsoft
prior to the actual physical migration.The principalExchange 2003 system and deactivate the legacy
issues of concern in any migration to a new mailsystem.A burn-in period should be identified, over
service are data integrity and transparent cutover towhich the Microsoft Exchange 2003 system must be
production. Data integrity guarantees that all mailclosely monitored for error conditions.Using Migration
accounts, stored messages, and associated personalUtilities
information and preferences (for example, addressThere are multiple methods for the combined
books, passwords, and so forth) are accuratelymigration of accounts and mailboxes. One method is
retained in the new mail system. Transparent cutoverto transfer all accounts in a single migration. Then,
to production means that the transition is handledmailboxes can be transferred in batches. Another
quickly, cleanly, and with no disruption to themethod is to transfer a batch of accounts, then
end-user experience.In typical migrations, the totaltransfer a batch of corresponding mailboxes, and so
amount of time required for a successful transition ison.Utilities that support the chosen strategy must
a function of system complexity. Both the totalthen be developed and tested. These tests should
number of mail accounts and the total number ofinclude timing of the execution of these utilities.This
stored messages are significant factors. In addition,phase involves the building of the migration utilities
migration time can be affected by system andthemselves and must include the design,
site-specific issues.Any migration strategy mustdevelopment, and testing of the migration utilities
address:Migrating accountsMigrating mailboxesMigratingthat are to be used to migrate the mail from the
Accountsexisting system to the newly implemented Microsoft
This migration involves all of the information thatExchange 2003 system. New tools have to be built
uniquely identifies and describes a user, includingvery often because of the different source mail
class-of-service data that defines the service forsystems that can be in existence.Microsoft Exchange
which users are subscribed. Account data must be2003 offers automated migration tools designed to
placed in the Microsoft Exchange 2003 systemstreamline the process of moving your service,
before message data. The first task is therefore toincluding built-in tools for services using Sendmail and
collect and transfer account data from the legacySoftware.com's Post.Office. These flexible, modular,
system and then transfer it to the Microsoftand customizable tools are Perl scripts that handle the
Exchange 2003 system.If your legacy system hasexport of directory, mailbox, and user information
domains and organizational units, you must prepare tofrom these other systems to files in Microsoft
migrate these also.Migrating MailboxesExchange 2003-readable format (based on LDIF),
This migration involves message data--the actualwhich are then imported into Microsoft Exchange
messages to be migrated that belong to the user.2003. These tools enable you to migrate all accounts
The mailbox is simply a collection of the messagesat once or as incremental blocks of users. When
belonging to a particular account.Preparing themigrating from a different mail system such as
Migration PlanNetscape Messaging Server or SIMS, Microsoft
Migration involves significant planning, more so thanExchange 2003's proxy features and robust export
any other deployment task. This planning is necessarycommand set provide a solid foundation for rapid
because the activity is exposed to existing users anddevelopment of custom export scripts.Tips for a
will, in most cases, be the initial experience that usersSuccessful Migration
have of the new system. It is very important to planWith the completion of the migration tests, the only
for every eventuality in order to avoid problemsanticipated impact will be caused by the difference in
during the migration.Refer to Appendix A forfunctionality between mail systems. Once the
information on how to obtain a sample migrationmigration of accounts has started, the target
plan.Migration is 95 percent planning and 5 percentproduction environment becomes the production
execution. A multitude of factors that must beenvironment.The migration procedure involves these
considered in order for a migration to succeed.Thediscrete steps:Setting up Microsoft Exchange 2003 in
Migration Plan provides a detailed, step-by-stepProxy modeChanging the MX recordIdentifying
procedure for migrating accounts and mailboxes toaccounts to be migratedExtracting account
Microsoft Exchange 2003. The deployment teaminformationCreating accounts in Microsoft Exchange
should make several dry runs of this plan, with each2003Migrating messagesSetting Up Microsoft
dry run resulting in a subsequent refinement of theExchange 2003 in Proxy Mode
plan.Any migration plan should address theseMicrosoft Exchange must be configured for Proxy
considerations:Ensuring systems readinessCoordinatingmode prior to activating the system. The proxy
with other groups and identifyingconfiguration permits the relay of message and
dependenciesVerifying software installation andservice requests to the legacy system until the full
configurationSetting up the test systemProvidingmigration has been achieved.In Proxy mode, all
provisioning connectivityTesting the migrationChoosingincoming mail is directed to Microsoft Exchange 2003.
full or limited migrationResuming serviceEnsuringIf the mail is for a user that does not have an
Systems ReadinessMicrosoft Exchange account, the mail is relayed to
All systems to be tested must be ready andthe legacy system for delivery. If a user attempts to
operational before testing begins. In additionretrieve mail, but the user's mailbox is not yet located
networks must be implemented as defined in theon the Microsoft Exchange 2003 system, the POP
architecture design (see Chapter 2).For each originalserver will connect to the legacy system and will
e-mail system, separate IP settings (each with uniqueretrieve the mail from the legacy mailbox
"A" records in the DNS) must be established for thelocation.Changing the MX Record
following:Host Address This is the permanent IPIn order for mail to reach the Microsoft Exchange
assignment for the host.2003 system (instead of the legacy system), you
Service Address This is the address that is used bymust change the MX record in the DNS for the mail
all e-mail clients for a service. The Service Addressdomain of the site, so that traffic is directed to
will be re-assigned to Microsoft Exchange at the timeMicrosoft Exchange 2003.With all of the mail directed
of account migration.to Microsoft Exchange, you can begin to burn-in the
Service Proxy Address There must be a Servicesystem with live loads and become accustomed to
Proxy Address for each Service Address. The IPoperations administration even if there is no account
number used for any Service Proxy Address willdata in the system. However, as soon as the system
match its respective Service Address. The Serviceis activated, accounts are provisioned directly into
Proxy Address will be used for proxy targetingMicrosoft Exchange
where proxy is used on the Microsoft Exchange------------Note: This step can take a few hours to be
system. These can be de-assigned after all migrationspropagated over the
are complete and when it is determined that a revert-----------------Identifying Accounts to Be Migrated
procedure is not required.Coordinating with OtherThe first step in migration is to determine which
Groups and Identifying Dependenciesexisting mail accounts will move to the Microsoft
Since any migration touches upon many aspects ofExchange 2003 system. Accounts to migrate can be
a company's operations, make sure you coordinatedefined based on business rules (for example, all mail
the migration with all affected groups and identifyaccounts in good standing, or priority accounts
dependencies--that is, determining the order in whichrequiring early access to features not offered in the
systems should be migrated.Verifying Softwareexisting mail system).Extracting Account Information
Installation and ConfigurationAfter defining the accounts to migrate, the next
In addition to installing Microsoft Exchange 2003 (seestep is to extract account information from the
Chapter 3) and verifying that all componentsexisting mail system. Using the target account list,
inter-operate, you must set correct Microsoftaccount information is exported into a file in LDAP
Exchange environment settings for the root user.Data Interchange Format (LDIF). The standard LDIF
These include the correct $PATH,format permits the importing of account information
$LD_LIBARARY_PATH, and $Microsoft Exchangefrom any existing mail system to an Microsoft
settings in order to access the Microsoft ExchangeExchange system. The scripts used here can be
migration tools.Setting Up the Test Systemcustomized to handle any situation.Creating Accounts
To validate a migration plan, the test system shouldin Microsoft Exchange 2003
have the capacity of production systems, includingNext, accounts are created in the Microsoft
the proper storage volume configuration and failoverExchange directory based on the account information
configuration (service continuity). The test systemdescribed in the LDIF file. As accounts are created,
must have Internet connectivity, as Proxy modethey are placed in Proxy mode, causing mail delivery
operations cannot be tested without this.Aside fromto and access from unmigrated accounts to be
equipment that mimics the production system, testpassed directly through to the old mail system, thus
driver machines must also be available to power theensuring continuous service to end users. During this
migration and capacity tests. The test drivers mustphase, if a user logs in and supplies an unknown
be configured with migration utilities as well as withusername, the Microsoft Exchange POP server
mail clients or other test utilities for accessing andconnects to the current e-mail system.Migrating
sending mail.At least one test host is required forMessages
migration testing; this host acts as a surrogate forThe last phase of migration involves moving mail
the actual online e-mail hosts and holds all mailboxmessages from the existing mail system to the
data required for testing.Providing ProvisioningMicrosoft Exchange system. Message migration may
Connectivityoccur either as separate files or as a single,
The provisioning interface must be validated beforeconcatenated file. However, some customization is
migration can occur. C API procedures should betypically required, since the way a message is stored
tested to ensure that modifications performed onin the Message Store Server (MSS) can differ from
the ISD are successful and are propagated to thethe standard mail format. This phase requires new
provisioning database. The Perl API set for batchaccounts to run in Maintenance mode, during which
account migration also must be tested. Last,time these mailboxes are unavailable. For this reason,
administrative routines in the provisioning system ormessage migration is typically performed in small
ISD must be validated.This testing is performed in aincrements during off-peak hours.Exchange Migration
dual provisioning environment. The purpose of dualplan for moving forward:Perform Due Diligence on
provisioning is to ensure the ability to revert to theyour network via Remote Terminal Service ( Next
legacy mail system in the event that the new mailWeek)
system in not successful.For provisioning, automaticIdentify existing components - users, groups, login
mailbox creation must be tested. Zero-lengthvariables
mailboxes are typically not migrated; rather, they areDocument proposed AD structure
turned on in Microsoft Exchange 2003. The first timeProject kickoff meeting (Friday)
mail is received or checked, the mailbox can beInstall Windows Server 2003 (Friday Night)
created. A large test database (representing theInstall Active Directory (Friday Night)
volume of anticipated accounts) must beConfigure, Patch and Connect (Friday Night)
test-migrated to ensure that the procedure worksReview Event Log, resolve any errors (Friday Night)
and that the destination ISD database can handle it.IfConnect AD environment to existing Windows 2000
possible, you should identify a group of "friendly"(Friday Night)
users willing to assist in identifying any problems orIdentify existing printers (Saturday)
errorsTesting the MigrationIdentify existing components in Exchange (Saturday)
Before the migration can occur, comprehensive
testing on the production system must be completed.Build Exchange, configure, patch(Saturday)
Migration test activities are "non-intrusive" to theInstall and configure virus software,Spam solution
existing mail system and are conducted from aand Fax Software(Saturday)
separate system using actual user accountConfigure OWA in DMZ(Saturday)
information and a test copy of the production userVerify Installation (Saturday)
data.The procedures for extracting account dataPerform Mailbox Move (Saturday)
from the legacy system must be tested. TheInstall Outlook 2003 on all desktops. (Saturday -
method and utilities to load these accounts into theSunday)
ISD must be validated through testing. Each class ofReview Event Log, resolve any errors (Sunday)
service must be included, as well as each combinationSetup Test workstation/perform testing (Sunday)
of account attributes, such as forwarding, aliases, andOn-Site to handle any issues with the migration
vacation replies.In addition, the process of moving(Monday)The above steps are only an estimate of
mailboxes to the Microsoft Exchange 2003 systemwork needed to be perform a successful migration.
must be tested. This process includes the method ofAfter we perform the Due Diligence Intercore will
suspending the account, the physical transfer ofhave a more definite outline in MS Project to fully
messages and attachments, and the return of thedetail the breadth of work needed to perform the
account to active status.You should make anymigration . This Due Diligence will identify issues that
possible configuration changes to prevent network orwe can resolve before the migration is
system loading. In addition, you must establish anyperformed.InterCore Technologies, LLC opened it's
special network, host, or storage accommodationsdoors in May of 1996. Our mission: To Provide a high
that may be required for testing. A special networklevel of computer consulting services using the most
configuration may be required to prevent trafficexperienced engineers at fair prices. We believe in
complications introduced by migration testing. Anotherusing a Business Value approach to every aspect of
solution may involve localization of the original mailboxcomputer consulting. This provides our clients with
storage to the Microsoft Exchange 2003the most cost effective solutions. We help our clients
----------------Note: Depending on the particulars of aget more with their current technology investment.
given migration, you may need to create new scripts