Re: Return a Debian system to a pristine state
On Tue 02 Jun 2020 at 11:03:48 (+0700), Victor Sudakov wrote:
> David Wright wrote:
> > On Sun 31 May 2020 at 16:28:34 (+0700), Victor Sudakov wrote:
> > > David Wright wrote:
> > > > On Fri 29 May 2020 at 21:57:06 (+0700), Victor Sudakov wrote:
> > > > > David Wright wrote:
> > > > > > Finally, pkg delete -a sounds like something from the abattoir,
> > > > > > rather than anything you'd do to a pet (to use your analogy).
> > > > >
> > > > > It's not as terrible as it sounds ;-) It's more from a vet clinic than
> > > > > from a slaughterhouse. You don't lose configs, you don't lose network
> > > > > connectivity or remote access during this procedure. You can save a list
> > > > > of installed packages before deleting them, and reinstall only those you
> > > > > know you need.
> > > > >
> > > > > Unfortunately, the FreeBSD package system is not as mature as DEB or
> > > > > RPM, therefore until very recently the "pkg delete -a" procedure has
> > > > > been required to get rid of the dependencey hell.
> > > >
> > > > OK, that sounds more like what people do on Windows systems, where
> > > > there's a reset option, except that on Windows you can, ISTR, lose
> > > > all your own files if they're under C:.
> > >
> > > Since what version does Windows have a reset option?
> > No idea. The last version of Windows that I used was IIRC 3.11.
> > I parted company when W95 came with "DOS" 7 rather than a
> > successor to DOS 6.22.
> Ah, I thought you knew something I did not.
No chance of that.
> Then no, Windows still does
> not have a reset option.
I don't know how you define "reset option". I was just employing those
words with their generally accepted meanings: reset means "set again",
in the sense of "restore", and option means "through choice". You
obviously have a more technical meaning in mind.
> > > For dozens of
> > > years, literally, Windows has been notorious for leftovers of removed
> > > programs remaining in the "base system" and causing unexpected effects.
> > > There were even commercial products on the market to purge those leftovers.
> > You're way ahead of me on Windows, then. I just know what I've seen,
> > and what I saw was this:
> > Chapter 3. Lenovo OneKey Recovery system
> > The Lenovo OneKey Recovery system is software designed to back up and
> > restore your computer. You can use it to restore the system partition to its
> Such things are present in some laptops, but they are not part of
> Windows per se, they are developed by equipment manufacturers. Usually
> they just extract an OEM image of Windows from some recovery partition
> in case a user renders his/her system unbootable, as was verbosely
> quoted below.
Well, what you are asking for in your subject line concerns Debian,
so I chose to make this analogy in quoting that source:
an OS is part of a computer system,
Windows is part of the Lenovo system purchased,
Linux is part of a Debian system.
What counts as a "reset option" for Linux, as opposed to Debian?
> > > FreeBSD is different in this respect. No part of third-party software
> > > ever gets into the base system (unless you install something manually
> > > and incorrectly).
> > This has already been pointed out, that Debian's installed system is
> > an individual outcome, not some sort of mandated selection.
> > > And of course you don't lose any user data if you run
> > > "pkg delete -a"
> > I didn't know we were discussing user data at all.
> Apparently we were. Let me quote your own words among others:
> "... ISTR, lose all your own files if they're under C:"
That partial quotation omits the opening words. The paragraph was:
OK, that sounds more like what people do on Windows systems, where
there's a reset option, except that on Windows you can, ISTR, lose
all your own files if they're under C:."
The example of Windows was brought up in response to your mentioning
"dependency hell", something I remember well when my institution
upgraded their Windows users to W95. And with Windows, you don't
"own" C:, even though many users leave their own files there. In
Debian, you "own" /home, which is why there's no need to discuss it
here. (Whether you decide to wipe the filesystem containing /home is
up to you, of course.)
> > > > Debian doesn't work that way: you can remove packages from the system
> > > > at will in a controlled manner. Isn't that what sysadmins do?
> > >
> > > Well, I was not feeling particulary sysadmin-ish about the desktop
> > > system I wanted to cleanup.
> > How you feel about it can't alter the fact that reverting a system by
> > removing packages is a sysadmin-ish process: you administering the
> > system.
> This is more of a terminological question.
As is the definition of "pristine state" for a Debian system.
> Is a user installing or
> removing GIMP of FireFox really administering a system? Some
> administrative tasks are easy enough to be performed by users, and maybe
> (just maybe) the removal of extra software should be easy enough
> to be user-serviceable (i.e. not carry the risk of killing the system
> itself, or require sysadmin knowledge and reading of manual pages).
If you don't want to overthink it, then you could treat the
root/user prompts as distinguishing sysadmin/users.
> > >
> > > Is the /usr/sbin/policy-rc.d method still the official supported one of
> > > disabling this behavior when it is not desirable?
> > It's many years since I ran servers in what one might call "hostile"
> > environments, so the current situation suits me, and I don't keep up
> > with discussions like those in
> > https://manpages.debian.org/experimental/policy-rcd-declarative/policy-rc.d-declarative.8.en.html
> It's an interesting development, I'm positively interested. Do you know
> if I can somehow subscribe to see what's happening in this direction?
¹ This far down the post, which mainly discusses my unfortunate aside
mentioning Windows, most sensible people have already pressed D[elete],
so there may be no replies to this appeal.