Re: Migrating IMAP (nnimap) servers?

["Bruno Hertz" <spammer.go.home@gmail.com>]

Bruce Stephens <bruce+usenet@cenderis.demon.co.uk> writes:

> "Bruno Hertz" <spammer.go.home@gmail.com> writes:
>
> [...]
>
>> I'm not totally sure, so additional comments are welcome, but afaik
>> all the marks Gnus maintains locally for news are stored as imap
>> flags on the server, like read, seen, ticked and even dormant (might
>> depend on your Gnus version, though). So just switching servers
>> should go alright without further actions in this regard, if the
>> flags are migrated, too.
>
> That sounds hopeful.
>
>> What I'm not sure about is what to do with possibly cached articles.
>> Maybe somebody else can tell more?
>
> I've not used those (with imap, anyway).  I'd guess that there'd be an
> issue with those---presumably it uses some kind of numbering, and
> presumably that's the server-specific article number.

Actually, thinking about it, you don't even need to 'switch', since your
mail servers are (presumably) part of your secondary select methods.

I.e. you could just add the new server there, subscribe to your folders
when it's online and see what it gives. If the old server is down by then,
Gnus will put it offline anyway, and you could remove it from your
secondary selects then or maybe even kill the subscribed folders one
by one and then kill resp. remove the server. So yes, I'm pretty sure
it should be no problem, especially when the migration is done
properly on the server side.

Finally, if you're concerned about loosing mail on the server side,
you could pull it before migration yourself to either maildir format
(fetchmail, procmail - don't know what happens with the flags in this
case though) or even to another imap server of your choice (mailutil
from uw-mailutils).

Regards, Bruno.