Having just mistakenly performed a large upgrade including powerdns, I’m
wondering if there isn’t something we can do to minimise the amount of
time we stop a service between pre-inst and post-inst. Could we have
something like a post-unpack maintainer script or a flag telling dpkg
that the package contains a daemon and to minimise the time between the
maintainer scripts where possible.

Yes I should read the list archives, but I’m about to go
out. Must remember to check when I get back.

Edit: Adeodato Simó pointed
out that in most cases daemons should just do a restart in the postinst,
unless changing files on disk is a problem. Need to investigate if this
is an issue for pdns-server and fix it.