I've asked this before, but now it's time to move one server to another, I can't delay the operation anymore (the older server is failing)

Both server are pretty old: 1.2.15

Probably, faster way would be to rsync all mailboxes from the older server to the newer one. I can start migrating everything while running then, stop the older server and sync only what is changed, keeping downtime at minimum.

Any better solution ?

It depends on your situation.

If you only have a small userbase with modest amount of mail, you can probably take your whole system down, do a one time migration, then cut over to the new system without too much downtime.

If you have medium sized operation, then what you propose above would work.

If you have a large userbase (or large user mailboxes), or you want to minimize downtime, you can incrementally migrate per user so that any particular user experiences a small window of outage, but the system is online for everybody else. This, of course, requires a lot more setup and planning.

Joseph Tam <jtam.home@gmail.com>