[TriLUG] Upgrade Debian 7 to 8

[Erik via TriLUG]

I've been doing rolling upgrades for over a decade on various Debian
systems, usually on sid. I tried 'testing' a few times, but the automated
way packages move from sid to testing tended to cause more issues then
the way sid ("unstable") gets populated.
The worst upgrade issue I've had is something like a libc upgrade forcing
me to manually roll back a couple packages. Or something that caused an
unresolvable error that meant that apt rolled back or refused to install,
and I held off on dist-upgrading for an extra week or two.

Apt and dpkg are really great about keeping everything (from
configs to dependencies) contained in a manageable space, so if you
don't do too many things at once, you usually don't have a cascade of
packaging cruft to undo. RPMs on the other hand... *shudders*

*Systemd* should still be very optional, you can even just
'apt-get remove systemd' and it will bring back sysv, you may need to
restart to swap out the init process though.

Systemd co-opting ntpd, along with not offering me anything for
long-uptime servers worth beta testing a new system structure for,
has kept it off my machines for the forseeable future. I don't struggle
enough with daemon management to want to deal with systemd config files
instead of init scripts or supervise run files.

Ergh sorry, I managed to forget about systemd's vast array of presumptions
and assumption of responsibilites for a few months, and it's all just pouring out now. :/


After you update your sources.list (or the conf sub-directories if you nasty)
definitely run 'apt-get upgrade' before a dist-upgrade. It will help
catch some corner cases when too many things are changing how they run
at once. It will also help you dodge new packages like systemd early.
You could also use apt pinning or something to stop it from showing up in
the first place, but ugh, effort.

You can also do a dist-upgrade, and see what the list of packages is,
and then just copy the ones you want to upgrade and install them
directly. Installing a few packages at a time can be a good way to
remain aware of what needs to be on your system, and what depends on what.

Also, you can copy (or 'dpkg -i') old .debs out of /var/cache/apt/archive/ if your
system isn't auto-cleaning them. Handy for a quick roll-back without
having to look up the package on http://snapshot.debian.org/


On Fri, Sep 09, 2016 at 01:21:43AM -0400, Ric Moore via TriLUG wrote:
> On 09/08/2016 03:49 PM, Grawburg via TriLUG wrote:
> > I understand I can, with care, upgrade my Debian 7 to 8 (Jessie)
> > without a totally new install. My question is simple: Am I asking for
> > trouble doing it this way instead of doing a fresh install on a new
> > HD?
> 
> 
> There is a great likelihood that it will end in tears. There is the jump to
> systemd to consider. It blew up on me, but my installs don't stay "stock"
> for long! So, I'd have a freshly pressed install DVD  handy just in case.
> Then you can do as you darn well please. :) Ric
> 
> 
> -- 
> My father, Victor Moore (Vic) used to say:
> "There are two Great Sins in the world...
> ..the Sin of Ignorance, and the Sin of Stupidity.
> Only the former may be overcome." R.I.P. Dad.
> http://linuxcounter.net/user/44256.html