Migrating User Accounts - and ImapSync

[kirme3]

I'm getting ready to migrate all users from a SquirrelMail/WebMail/GroupOffice Mail system to Zimbra. I've tested the ImapSync utility and it seems to do what I need, but it seems a little slow for the timeframe I have. Essentially, I have 37,000+ accounts to migrate in a 3 day period. Does anyone know of any other options out there that I may have? Also, does anyone know the type of load imapsync has on servers? From what I can tell, it's not too terrible. My current plan is to do a bunch of imapsync processes at the same time, but I don't want to overdo the load on the source servers or the Zimbra servers.

Anyone else have any thoughts?

Thanks!

[romulo]

Hi kirme3,

Do you use postfix ?

If yes, you can use to Transport Maps for migrate the users partially, thus increasing the timeframe. If you want to know more details, I can send for you.



Rômulo Giordani Boschetti
Interop - Brazil

[KevinH]

Your best bet is to start/run the initial imapsync many days before.. What we usally do is run it in the non-busy periods at night moving over batches of users. Then in the *real* 3-day window to move user's you just need to run imapsync on each account but it will be very fast since it only needs to sync/move the changes. You can also run more than one imapsync at a time basically depends on your hardware and how much read load the current server can handle and how much write load your new Zimbra server can handle.

[kirme3]

The problem with trying to sync many days/weeks before is knowing the passwords. We are in the midst of setting up a parallel mail server that we will be rsyncing the mail to so we can have user accounts with passwords we know. We'll then do the imapsync for weeks prior to final migration. Then, like you said, when we are ready to do the changeover we'll just have a day or 2 worth of email's to migrate, making things go much faster for us. Hopefully 4 weeks of syncing is enough.

Thanks for the help.

[kirme3]

After testing my parallel system, it looks like this will be a valid solution, except for one thing.....It looks like some additional header information is being written. I started migrating accounts with our current production server. When we decided it was going to take too long, I set up the parallel, offline servers that I am using rsync to bring over the data to. When I tested on an account that had some mail in it already, it doubled up a lot of messages. Upon looking at the header info, there were a few changes to the headers, which I believe is what caused the mail to double up. Has anyone else seen this? Or could this be simply from the parallel/offline system?

Also, when I tested the --delete2 option, it seems like the emails weren't getting deleted that should have been. Does Zimbra have trouble with that?

Thanks.

[KevinH]

It should not duplicate the mail. What are you seeing in the headers?

[kirme3]

I was getting different headers...the parallel system was modifying the headers which made imapsync think they were all different emails. After clearing out the accounts and just syncing form the parallel system, mail wasn't duplicating.

[rmanola]

Originally Posted by romulo

Hi kirme3,

Do you use postfix ?

If yes, you can use to Transport Maps for migrate the users partially, thus increasing the timeframe. If you want to know more details, I can send for you.



Rômulo Giordani Boschetti
Interop - Brazil

Hello, I'm interested in that solution, can you provide me with more information?