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For organizations that currently have
Exchange 2000 or Exchange 2003 looking to migrate to Exchange 2007, the
migration strategy pretty much involves replacing front-end servers
with Client Access servers, bridgehead servers with Hub Transport
servers, back-end servers with Mailbox servers, and adding in Edge
Transport and Unified Messaging servers as desired. There is a very
specific order that works best in the migration process as well as tips
and tricks that help you navigate around known migration challenges.
Note
There
can be several variations of an existing Exchange 2000 or 2003
environment where the organization has clustered back-end servers, or
has an SMTP relay server ahead of the Exchange environment, or has
servers residing in different physical sites that can still use this
migration process. There are no migration limitations that prevent an
organization from using this migration strategy and making variations
to it, including migrating onto a clustered Mailbox server, adding Hub
Transport or Client Access servers, or consolidating servers as part of
the migration process.
Planning Your Migration
The
planning process in migrating from an environment that has Exchange
2000 or 2003 to Exchange 2007 involves ensuring that the existing
environment is ready for a migration, and that the hardware necessary
to accept the migrated server roles is compatible with Exchange 2007.
The planning process to Exchange 2007 proceeds using the following path:
1. | To become
familiar with terminology used in Exchange 2007 design architecture. | 2. | Confirm
that you want to do a one-to-one migration of servers from Exchange
2000 or 2003 to Exchange 2007 (that is, Exchange 2000 or 2003 front-end
servers become Exchange 2007 Client Access servers, and Exchange 2000
or 2003 back-end servers become Exchange 2007 Mailbox servers).
Note
As
part of this migration, you can do server consolidation by moving
mailboxes from multiple servers to fewer servers, migrate from basic
Exchange 2000 or 2003 servers to clustered 2007 servers, or add in Edge
Transport or Unified Messaging server role systems as part of the
migration process. These variations just need to be slipped in to the
migration plan.
| 3. | Select
the proper version of Exchange Server 2007 in which you will be
implementing Exchange 2007 on, whether it is the Standard Edition or
the Enterprise Edition of the server software.
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The
Exchange Server 2007, Standard Edition is the basic messaging server
version of the software. The Standard Edition supports five data stores
and has full support for web access, mobile access, and server recovery
functionality. The Standard Edition is a good version of Exchange to
support a messaging system for a small organization, or as a dedicated
Edge Transport, Hub Transport, or Client Access server for a larger
environment. Many small and medium-sized organizations find the
capabilities of the Standard Edition sufficient for most messaging
server services, and even large organizations use the Standard Edition
for message routing servers or as the primary server in a remote
office. The Standard Edition meets the needs of effectively any
environment wherein a server with a limited database storage capacity
is sufficient.
The Exchange Server
2007, Enterprise Edition is focused at server systems that require more
Exchange messaging databases and support for clustering for higher
availability. With support for up to 50 databases per server, the
Enterprise Edition of Exchange 2007 is the appropriate version of
messaging system for organizations that have a lot of mailboxes or a
lot of mail storage, and for an organization that wants to set up
clustering for higher reliability and redundancy of the Exchange
environment. Although clustering used to be considered something that
only large enterprises implemented, Exchange 2007 supports Cluster
Continuous Replication (CCR) that provides mailbox redundancy as part
of a disaster recovery process. CCR clusters Exchange and associated
mailboxes across a local area network (LAN) or wide area network (WAN)
segment, thus providing remote site failover in the event of a primary
server failure. If the organization is considering using Exchange
2007’s CCR capability, the Enterprise Edition is required for the
Mailbox server roles in the organization.
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| 4. | The
next step is to acquire the appropriate hardware necessary to implement
the new Exchange 2007 environment. Remember that Exchange 2007 now
requires x64-bit hardware and Windows 2003 x64-bit edition operating
system software. Table 1 highlights the minimum hardware requirements.
Table 1. Minimum Hardware Requirements| Hardware | Minimum Requirements |
|---|
| Processor | Intel Extended Memory 64 Technology (Intel EM64T) or AMD Opteron or AMD Athlon 64 processor, which supports AMD64 platform
| | Memory | | | Disk Space | |
Note
The
variables to an Exchange Server 2007 environment are random access
memory (RAM) and disk storage. Because 64-bit systems now support more
than 4GB of RAM and actually require 1GB of RAM plus 7MB per user, it
has been found that most Exchange 2007 servers have 16GB to 32GB of RAM
in the system as the base configuration (more memory for servers
hosting thousands of users). Instead of spooling or caching
transactions primarily to disk, Exchange 2007 takes advantage of memory
for caching transactions. For disk storage, Exchange 2007 does not
require more disk storage than previous versions of Exchange.
Therefore, as a rule of thumb, choose Exchange 2007 server hardware
that has enough storage space to hold the current Exchange database
plus plenty of additional storage space for the growth needs of the
organization.
| 5. | Confirm
that the current Exchange 2000 or 2003 environment server components
are compatible with Exchange 2007. If
there are components such as the GroupWise Connector for Exchange, Key
Management Server, or Exchange 2000 Conference Service, those services
need to be migrated to current technologies that are supported in
Exchange 2007. In the two sections referenced in this paragraph,
workarounds are noted to address these issues.
| 6. | Validate
that add-ons and utilities used in the existing Exchange 2000 or 2003
environment are compatible with Exchange 2007 or upgraded to support
Exchange 2007. This includes products like BlackBerry services, Cisco
Unity voice mail services, tape backup software, and so on.
Note
If
a software program is not compatible with Exchange 2007, many times you
can keep the software operating on an older Exchange 2000 or 2003
server, and migrate the rest of the environment to Exchange 2007. This
can typically be done for gateway tools that route information in to or
out of an Exchange environment.
| 7. | Make sure to bring the Exchange 2000 or 2003 environment into a Native mode effectively eliminating any Active Directory
Connectors (ADCs), site connectors, Site Replication Service (SRS)
connections, and so on.
| 8. | Test
the migration process in a lab environment to confirm all of the steps
necessary in migrating to Exchange 2007. The test migration is covered
in the next section. |
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