Upgrading from Cyrus 2.1 to 2.3 (question about backends)

[Andrew Morgan]

On Mon, 31 Mar 2008, Steeve Gagnon wrote:

> Hello !
>
> We are planning an upgrade to Cyrus 2.3.7
>
> Currently, we have some servers, running different versions of Cyrus mail :
> - mupdate running Cyrus v2.1.18
> - 2 frontends running Cyrus v2.1.18, others frontends running v2.2.12
> - All our backends are running Cyrus v 2.2.12
>
> Our goal is to upgrade all servers to Cyrus 2.3.7 (version provided by
> Redhat), but I have pressure to install some bakends at first, then
> after, upgrade the others servers. Of course, I would prefer if these
> new backends could use Cyrus 2.3.7
>
> So my question is :
> Do backends running Cyrus v2.3 work with an mupdate server running Cyrus
> 2.1 ?
>
> Until now, as a test, I installed a frontend running 2.3.7 and it seems
> to work fine with our mupdate server (but I didn't make intensive
> tests). But, before reconfiguring this server as a backend, I did a
> ctl_mboxlist -d (dump Cyrus database) and realized that the output
> doesn't have the same format as for version 2.2.12 : It seems to have an
> extra field (probably the mailbox type flags ?).
>
> So, since I don't really have a true environnement for testing, I'm less
> willing to insert a new backend running Cyrus 2.3
>
> So my question remains :
> Do someone knows if a Cyrus backend v2.3 can run fine with a Cyrus
> mupdate server running version 2.1 ?

See my thread from December with the Subject "mixing versions in murder". 
I can't answer if it is safe to keep your mupdate server at version 2.1, 
but I can tell you that you cannot use v2.3 frontends with v2.2 backends.

 	Andy