Last weekend we completed our migration of over 1000 faculty and staff from GroupWise 7 to Zimbra with the Zimbra web client as our supported client. What a long, strange trip it's been.

If you're planning a migration from GroupWise, be sure to read Rich Graves' excellent posts on the topic. Rich's script for recreating proxy rights as shared folders was particularly helpful. I wish I could contribute as much detail has he has, but we've been nose to the grindstone for the last month to make our dates and much of the detail is a blur at this point.

In our environment a staged migration with a split domain was considered unacceptable because of our heavy use of calendar features and the need for free/busy visibility. Instead we chose to migrate users in the background in the weeks leading up to the cut-over, and then migrate them once more to update their mailboxes on the weekend of the cut-over. This was a mistake.

The morning of go-live was a mixed bag. Whatever excitement there was for the new application was overshadowed by concern over missing messages and appointments. We are still working a week later to clean up all the missing messages and broken calendars. We'll have to leave our GroupWise system available for at least the next few weeks as users check for more missing messages and fix their calendars. The primary reason for this is the GroupWise migration tool.

If we had this to do over again we would not use the GroupWise migration tool. We've found that we get better and more reliable results with imapsync. For calendars we've gotten better results by exporting the user's calendar to an ICS from the GroupWise client and importing that to Zimbra. Obviously that would mean doing users one by one with a split domain but we've effectively ended up having to address every user individually in one way or another anyway.

When we started the migration process we managed to grossly underestimate the time required to do the migrations - mainly because of problems with the GroupWise migration tool. That resulted in our date slipping by a month which was a black eye right from the start. The GroupWise migration tool has issues. Zimbra has worked with us to overcome some of the issues but many issues remain - some of which we're still discovering.

The biggest problem with the tool is that it frequently crashes and dies. That could have something to do with the integrity of the GroupWise mailstore, but the tool shouldn't just crash no matter what GroupWise feeds it. During the course of the migration, updates to the tool reduced the frequency of crashes from about 30% to about 10%, but that's still a lot when you're migrating over 1000 accounts.

When it dies, the best you can do is dig up the migration log (it will be in the application's temp directory) and determine the date it was migrating messages for when it died. You can then restart it for the day following and if you're lucky it will complete. Of course, you're losing part of a day of mail for that user in the process.

When the tool runs successfully, there are other problems to deal with.

  • On one of the migration tool releases the registry key for the attachment size limit changed, leaving us with a lot of unmigrated attachments. Never mind the fact that it make no sense that this is hidden away in a registry key in the first place.
  • The migration tool doesn't reliably recognize what it has already migrated. To avoid duplicate messages we had to use the "migrate after this date" feature.
  • Calendar migration is a crap shoot. Many appointments are duplicated, time shifted, or dropped.
  • Messages that were forwarded as an attachment within GroupWise lost their attachments during the migration.
  • When we applied our commercial cert just prior to going live, the migration tool stopped working completely. The only solution offered so far is to put back the self-signed cert when we need to do migrations.


The GroupWise migration tool is a moving target with regular updates. Maybe by the time you're ready to migrate from GroupWise the problems will be fixed. But if you're thinking about doing a migration from GroupWise I'd strongly recommend that you do substantial testing of the migration tool before counting on it for your migration. Check the results with actual users and bare in mind that even if you do engage users in helping check the results (as we did), many won't bother really looking at their mailbox and appointments enough to find the problems until they have to actually use it.

The jury is still out on whether we'll be able to call our switch to Zimbra a success. Issues around the quality of the migration have mostly obscured user reaction to the new application. We are getting some praise and some complaints on that front that I'll talk some about in a later post.