Scary Exchange

Certain life events are supposed to be particularly stressful. I cannot remember the whole list right now, but if I mention that moving house is one of the oft-quoted leaders you will know what I’m talking about. Well, I’m going to extend the list slightly by appending ‘contemplating wholesale changes to a mail server’ – a situation that arose for me this month when it became necessary to move a Microsoft Exchange Server 2003 box from one location to another. Being a good boy, I was sure to first of all sit down and compose a neat list of ‘things to do’. Such lists can sometimes be scary, and as I progressed further down this one I realised that it was far scarier than most, because of the obvious potential for something nasty to happen if certain stages went wrong.

This was also a time of contemplation, because a decision had to be taken as to whether to start afresh or whether to try and modify the existing setup. I wasn’t at all in favour of the latter option and intended to blow the whole box away and start again from scratch – the only catch, of course, being that I would need to be sure that all the message files had been successfully backed up and stored ready for shoving back onto the newly set up server. My initial idea was that the hardware should remain the same, but then I decided to err hugely on the side of caution and set up a completely fresh system, leaving the original configured as before with all the old messages and settings intact. When you consider that Exchange Server is not exactly shy when it comes to the settings department, this wasn’t a bad idea at all.

If you really do need to blow away the existing box and do a reinstallation, there are more than a few areas that will need attention and more than a few dialog boxes you will need to probe to glean the crucial information that’s hidden away therein. For example, you will need to examine the Properties dialog for the default recipient policy, filtering rules and so on.

The first job, however, was to run a backup; I did two, one using the default Windows Backup software, which was nice and easy, and a second using a tool called the Exchange Server Mailbox Merge Wizard (known as ExMerge for short), which was less so. For the first backup, I launched the built-in backup system in Windows Server 2003 via Start | All Programs | Accessories | System Tools | Backup and then chose Exchange Server from the list and progressed through the wizard. This gave me a BKF file, which I carefully stored away on another server and on a DVD too for good measure.

The next thing to do was to employ the services of ExMerge. This utility is designed to enable an Exchange Server administrator to get all the data out of the mailboxes on one Exchange Server and merge them into the same mailboxes on another Exchange Server – the ideal tool, therefore, for what I had in mind. You can run ExMerge in One or Two Step mode. In One Step mode, data gets copied from the source mailbox to a PST file and then that data is merged into the same mailbox on the new server, which requires the mailboxes to have the same container path, name and so on.

Alternatively, you can use the tool in Two Step mode, which is what I went for. In this mode, you perform step one, which is the extraction of data from mailboxes to PST files, and then you can run the utility again on the new server box at some point in the future and perform step two, which merges these PST files into the server’s mailboxes.

There is an excellent Microsoft Knowledge Base article on this topic if you visit their website at support.microsoft.com

Once I had the PST files safely saved away, I made some copies and checked them in Outlook. All was fine. The next step was to build my new box, so on went a copy of Windows Server 2003. I installed Active Directory and made it a Domain Controller, installed DNS, set it up as a Global Catalogue (GC) server, patched it to the hilt and finally installed Exchange Server 2003, which I also patched up to date. Now came the moment of truth: I installed ExMerge on the new box, fired it up and went for Step Two of the migration process.

Now, I should point out that while using the standard Windows Backup to create the BKF file hadn’t taken all that long, using ExMerge in a Two Step operation took the best part of a day and I was only dealing with four or five gigabytes of data and a small number of mailboxes. There were, however, no hitches, and once I would verified that all was working properly I was able to blow away the old server box and press it into its new role as a Terminal Services client, but that’s a story for another day.

As an aside, do make sure you have checked the default recipient policy settings on the old box and made a note of all the domains listed there before you get rid of an old Exchange server if you are hosting multiple domains. You will find these addresses by running the System Manager (Start | All Programs | Microsoft Exchange | System Manager) and then expanding Recipients followed by Recipient Policies. You now want the Properties for the Default Policy and then the E-Mail Addresses (Policy) tab.

I think what pleased me most about the whole process is that it all went so smoothly. The nerve-racking stuff like backing up and then copying and merging the mailboxes for once went like a dream. The only slight ripple in my sea of tranquillity was caused by the inordinate amount of time ExMerge takes to do its stuff, coupled with the fact that it often looks as though it is not doing anything. That apart, the only other problem I had was with patching the system software, because despite having a dedicated Software Update Services server running, plus the Microsoft Baseline Security Analyzer (MBSA) and its running mate Hfnetchk, I discovered that one Exchange patch had slipped through the net when I came to run ExMerge on the new box. Fortunately, a comprehensible error message pointed me to the Knowledge Base article that discusses this patch, and that in turn linked me to a download page, but I was still unhappy that the patch hadn’t been applied earlier. I have been considering beta testing Microsoft’s new update server package for a while now, and I think I would better make that the next item on my agenda.