Migrating active Server

[wheez]

Hey everyone!

I am thinking of migrating a cloudron server. I have looked at the docs and the general migration is clear to me and something that I have even done before.

Now for me the questions that comes into play is that this is quite an active server. There are multiple domains and around 30 active mail boxes of a company on there.

How would I go migrating this without losing data, especially on the mail server?

I am a bit worried that after I completed the backup of the server there might still be mail coming in and when I restore on the new server those will be missing.

Is there a way to have the server be offline, so no running app and mail server while doing the backup?

Thanks for your help!

[p44]

@wheez Watching this post and answers

[fbartels]

I do see two strategies for you mail migration.

1. do the migration when you think that no normal person would be sending mail at that time.
2. shortly before starting the migration close port 25 in your filewall. This will lead to a temporary sending failure for everybody that would try and if that person is not a badly configured spam bot it will try to deliver the same mail at a later time again.

[james]

Just adding a note:
For inbox synchronization you could also use imapsync afterward.
Maybe use the --dry option at first to confirm it works as expected.

[wheez]

yes @james I have also thought of using that. but manually running it on all mailboxes sounds like a pain I don't want to go through.
I guess the current way I envision it is writing a script for imapsync that uses the api of cloudron to get all mailboxes and impersonates the users of the mailboxes to auto run imapsync on them.

but then again maybe a block of the port is the way to go, so I don't have to write that script. the whole backup and recover process should be done quite quickly anyways.

I am wondering though if this is not something others have gone through as well?