Default User wrote: > On Mon, Jul 1, 2019, 13:51 Brian <[email protected]> wrote: > > What if a new Stable release introduces a major change to the existing > distribution technology or methodology? > > For example, a new default filesystem is introduced. Or something like > systemd infects the distribution or its rate of metastasis accelerates, > etc. Or an important package management system or communication protocol > is superseded or falls into disuse, or is simply abandoned by its > developers or maintainers. > > I was wondering if an existing Unstable setup could diverge so far from > Stable that major surgery would be necessary, or even complete replacement > with Stable, followed by conversion to contemporaneous Unstable.
Debian basically holds to two promises: it will be possible to upgrade in-place from one stable major version to the next stable major version; and, inside a stable major version, changes are made for security and bug fixing but not for the sake of new features. Let's look at the scenarios you presented, through three fairy-tales of complete fiction which bear no resemblance to any form of reality whatsoever: 1. Oracle implodes into a corporate black hole, leaving behind a bankruptcy administrator who sells the rights to ZFS and all related technologies and patents to the Free Software Foundation for $20 and a stick of fruit-flavored gum. Everyone decides that ZFS should be the new default filesystem. In this case, the Debian Installer would soon gain support for creating zpools and zfs, and new installs would use it by default. Existing installs would not be affected. 2. Lennart Poettering is anointed of heaven and a voice from the sky booms "All shall use systemd, pulseaudio and avahi!". No problem, all those packages are in Debian already. 3. Debian maintains the .deb format itself, so it can't be superseded (though it can be improved, and there's a versioning scheme.) Let's say that all of the OpenBSD hackers simultaneously upload themselves into cyberspace and stop supporting OpenSSH. There are other folks who can do that job, and the license is permissive, so it's legal. I imagine we probably get three competing SSH implementations, which isn't actually bad, since they aren't SSH if they can't interoperate. Now, an individual machine can, certainly, fall into an unstable trap where something majorish is both installed and can't be upgraded out of. At that point, I would strongly consider my previous life choices, and also write down the config, backup the data, and start again with a new machine. -dsr-
