[Dovecot] prevent dovecot from modifying maildirs

[Felix Rubio Dalmau]

Hi all,

        Is there any possibility to ask dovecot to write nothing to disk, 
something like a "read only" state, without shutting it down? I have set up a 
ZFS+postfix+dovecot mail server, and I need both postfix (postsuper -h ALL) and 
dovecot (¿?) to stop modifying the disk to create the snapshot to be saved.

        Does anybody has any idea on how to achieve this?

        Regards!
        Felix