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Advice needed regarding Exchange 5.5 to 2003 migration

Jeff Tennessen
Last Modified: 2010-03-06
We are currently running Exchange Server 5.5 on a Windows Server 2000 domain controller operating in mixed mode. We are beginning the process of migrating this to Exchange 2003 running on a Windows Server 2003 domain controller and migrating our domain to Active Directory. We really need the entire migration to be performed during a weekend, because any weekday downtime is really disastrous to our clients, who are financial institutions. We have had conversations with a local consultant about helping us with the migration, as our network admin has thrown up her hands and said it is beyond her. The consultant is adamant that the migration cannot be performed in 48 hours, and that we must plan to have our entire system shut down on either a Friday or a Monday -- or possibly both. The network admin agrees with them, saying that, "There is no other company anywhere that uses Exchange the way we do. We have more customization, automation, and leveraging of public folders and other groupware features than anyone else." (That is pretty much a direct quote.)

I am a programmer, not a network admin, and my experience with Exchange is mostly limited to developing custom solutions for the company on it, but I have to say that this doesn't ring true to me. We are a very small company (about 25 employees), and I simply do not believe that our Exchange implementation is somehow more complex than any other company out there. We have a custom COM add-in that automates filing eMail correspondence by Client based on the domain name of the recipient, a public calendar for keeping company-wide schedule information, some public folders with custom forms that facilitate the submission and approval of procedures, some log directories that are posted to by other custom software we've written, a couple of public contact folders that are leveraged by our fax server, and a few other miscellaneous things. But, to me, it is absurd to assert that this somehow constitutes the height of customization and complexity among all the companies running Exchange Server anywhere in the world.

I also find it hard to believe that the migration can't be accomplished in a weekend, given our size, but our network admin refuses to look for another consultant and so we are basically at a standoff. I guess I'm looking for some guidance here from experienced Exchange admins, especially those that may have performed a migration that is somewhat similar. Does anyone think the information we are getting from the consultant and our network admin sounds credible? Has anyone used a consultant for a migration of this nature that they would recommend highly? Are there any other suggestions you can give that would either help me make the case that we should not *ensure* downtime by building it into the plan (of course I realize that things can always go wrong) or help me see the light and get on board with what the consultant and network admin are saying?


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Donnie4572IT Manager

Do you have Active Directory?

Your migration can be done in less than a weekend.
25 users...you can migrate using PST's for that number of users.
Now, if you want 5.5 and exchange 2003 to co-existence using ADC, that is altogether different.

As for migrating all of your customizations well you should have a lab with exchange 2003 and work through implementations for that.

Something like..
Setup a test network and maybe using VMware or MS virtual machine
work through customizations until they work like you expect.

Setup 2003 DC/AD
Setup Exchange
setup all user accounts creating mailboxes
From all users desktop, export all mail objects to pst
disjoin from old domain
join to new domain
setup outlook to connect to new mailbox
import PST

There are many other ways to migrate but for 25 users I think I would go in this direction and depending on the amount of mail I would say about one day to a day and a half to complete.

Obviously, you may have much time invested in testing but for the cut over should only be about a day.

Jeff TennessenAssistant Vice President


OK, thanks for that advice. Our domain is currently mixed NT/AD, and we want to set up a new pure-AD domain as part of the migration. Once Exchange is migrated to 2003, however, 5.5 will go away, so they do not need to co-exist. Do the migrations to the new AD domain and the Exchange migration have to happen at the same time or could the domain be migrated one weekend and Exchange another?

We did at one time (this was a few years ago) have a testbed setup to test the migration. That is where our network admin ran into trouble and gave up on it. However, at that time virtualization was not as commonplace as it is now, so it was done with physical boxes, and was difficult to maintain. Your suggestion to do it through virtualization is a good one, and I am going to investigate that to see if it's a possibility. If it wasn't for the fact that I'd need the network admin's help to get it all set up and configured, I'd have no doubt, but since she is so dug in, I just don't know if she'll even consider helping.

Realizing that you aren't familiar with the specifics of our implementation, does your instinct tell you the migration is something a compentent IT staff of 3 people could do themselves with a little preparation and study or do you think we'd be better off with a consultant?

Thanks much!

IT Manager
This one is on us!
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Jeff TennessenAssistant Vice President


I can't tell you how much I appreciate your detailed and thoughtful answers. They are exactly what I was looking for!

Best regards,

Donnie4572IT Manager

Glad I could help. Good luck.
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