upgrading with murder/aggregator

[Andrew Morgan]

On Fri, 28 May 2010, Ragnar Sundblad wrote:

> Is murder/aggregator backwards compatible with older imap
> servers?
>
> We want to migrate form a single 2.1.18 cyrus imap server to
> multiple 2.3.x servers. An idea is to insert a common
> murder/aggregator in front of both the 2.1.18 server and the
> new servers, and seamlessly migrate users. Would this be
> doable?

Yes, you can do this.  However, your frontend proxy server must be running 
the old version until all of your backends have been upgraded.

Version 2.3 of the proxy server tries to issue commands to the backends 
that older version of Cyrus do not support.  I don't know if there are 
other incompatibilities between 2.1 and 2.2.

As always, it is a good idea to test this before exposing it to your 
users.  I suggest bringing up a 2.3 mupdate master, 2.3 backend, and 2.1 
frontend.  Then, use Cyrus' built-in mailbox rename/move feature to 
migrate a mailbox from the 2.1 backend to the 2.3 backend.  Test, test, 
test!

 	Andy