CASE STUDIES:
 
CASE STUDIES : ACTIVE DIRECTORY MIGRATION #1
 

A medium sized PR company asked us to undertake the migration of their aging Windows NT 4.0 based network to Windows 2003.

Technical Environment:

  • Single NT 4.0 domain
  • Four Windows NT 4.0 Servers: 1 PDC, 2 BDCs, 1 Member server
  • Two Exchange 5.5 Servers
  • +40 Desktop Computers running Windows 98, Windows 2000, Windows XP Professional

SOLUTION

We conducted a site survey to gather all details on the NT 4.0 domain, servers and client computers.
A precise migration plan with timeframes was then submitted and approved by the client’s management.

We decided not to carry out an in-place upgrade of the servers:

  • Hardware upgrades such as hardware RAID 5 or RAID 1 on all servers with new disk partitioning scheme
  • Important number of server applications to upgrade
  • In-place upgraded servers are not as stable as servers built from scratch

To preserve the NT 4.0 SAM database, a high spec computer installed as a NT 4.0 domain controller / Exchange server in the current NT 4.0 domain was introduced.

Promoted to a PDC and master Exchange 5.5 server with all mailboxes, system and public folders re-homed over a week end, we proceeded with an in-place upgrade of this NT 4.0 server to Windows 2003 / Exchange 2003.

This allowed us to progressively decommission the other servers and reinstall them from scratch with Windows 2003 while keeping the network up and running.

A couple of week ends after, all servers were running Windows 2003 and Exchange 2003 replaced Exchange 5.5.

The Active Directory FSMO roles were then reassigned to the reinstalled servers and all Exchange mailboxes public / system folders re-homed to the production Exchange 2003. The temporary domain controller was later decommissioned after we made sure that the upgraded network was stable with all post-migration issues resolved.

OUTCOME


The migration offered the following benefits:

  • Dramatic network uptime improvement
  • Reduction of daily IT issues
  • Reduction of network administration costs
  • Improved security by introducing of MS Software Update Services
  • Reorganization of network roles (file servers, print servers, DNS servers, WINS servers, etc.)

Our expertise allowed this client to keep their productivity unaffected by the migration. By adopting a progressive upgrade of the network with servers rebuilt from scratch instead of a straight upgrade of the operating systems, the client is now using the latest MS Windows and Exchange technologies with the highest possible system reliability while preserving the legacy user accounts and groups, and permissions on files, folders, Exchange mailboxes and folders.