Migration from an old server

barbero

Hello,
a customer asked us to migrate his old mailcow (August 2021 release) to a more recent version and on a new server.
We have seen that a simple update is not enough, because the versions docker-compose on the current server are stuck at version 1, while now version 2 is necessary.

Is there a guide for this type of migration and update?

Thank you for any advice you would like to share with us.

piperino

Have you had a look at this?
https://docs.mailcow.email/maintenance/migration/?h=mi

barbero

piperino
Of course, but it was precisely by following this guide that we had problems: the guide does not provide the possibility of migrating from a docker compose version 1 to one with version 2.

piperino

I would install new Docker Version on the new Server and restore data.
Or is that exactly the problem you have that you can’t restore existing data (with old docker) to the new machine?

barbero

piperino
Exactly: a simple restore with data from an old docker compose doesn’t work. Now we will try to copy the container images from the old one and update them to the latest ones.
We will proceed by trial and error: we hoped that someone had already had a similar experience that we could share and save some time!

DocFraggle

I guess it depends on how big the old mailcow system has grown in the meantime. If there are only a few mailboxes and domains you could install the latest mailcow on the new server, create them manually or via API (again, depending on the number of domains and mailboxes of course) and create sync jobs for every mailbox on the new server. After everything was synced switch over to the new server.
By doing this you don’t have to restore directly, I guess everything except for the vmail backup wouldn’t work anyways…

barbero

DocFraggle
Unfortunately there are many (too many) mailboxes and around 350 GB of mail to migrate and it is not possible to proceed in this way.

franck-grenier

Hello Barbero,
did you find a strategy for your update/migration ?

barbero

franck-grenier
we are planning a migration simulation, to highlight all the problems that arose some time ago when it was attempted and failed.

franck-grenier

Simulation worked for me from a 2020 release : https://community.mailcow.email/d/3405-upgrade-from-an-aold-mailcow-version/8