BALUG email was down on 2017-11-30,
it's back up again.
Sorry for any inconvenience.
I may put more details on relevant BALUG list(s)
sometime later. In the meantime, for the
interested/curious, see:
http://linuxmafia.com/pipermail/sf-lug/2017q4/013009.html
And as for the balug VM (which hosts most everything BALUG),
on 2017-11-30 it was updated from:
Debian GNU/Linux 8.9 (jessie) x86_64 (oldstable)
to:
Debian GNU/Linux 9.2 (stretch) x86_64 (stable)
excepting for the (non-Debian caused) email glitch,
all went quite smoothly and service interruption was
quite minimal. Key among minimizing service downtime
in general, under:
https://www.debian.org/releases/stretch/amd64/release-notes/ch-upgrading.en…
followed the procedures for:
"If the system being upgraded provides critical services for your
users or the network[2], you can reduce the downtime if you" ...
and additionally, obtained/downloaded all needed
packages in advance. E.g.:
# apt-get -y -d upgrade; apt-get -y -d dist-upgrade
... and that was after pre-filling cache
(/var/cache/apt/archives/) with .deb packages I already
had (from earlier downloads of package(s) and/or on Debian ISO(s)).