upgrade from cyrus imapd 2.3.11 to 2.4.9

[Bron Gondwana]

On Fri, Jun 24, 2011 at 03:32:50PM -0300, Patrick Boutilier wrote:
> I was planning to an upgrade from 2.3.16 to 2.4.9 by just shutting
> down Cyrus, installing new binaries, and then starting Cyrus again.
> This worked fine in limited testing (one account).

The only issue is that every first mailbox access causes an in-place
upgrade which requires a full scan of every email, so it can hurt
pretty bad for IO.

Bron.