[sf-lug] reinstalls, sweet used laser printer prices, ... Re: SF-LUG meeting notes for Monday 21 January 2019

[Michael Paoli]

> From: "Rick Moen" <rick at linuxmafia.com>
> Subject: Re: [sf-lug] SF-LUG meeting notes for Monday 21 January 2019
> Date: Fri, 25 Jan 2019 03:23:08 -0800

> By the way, I don't think it's good tactics to just install (or
> reinstall) everything you can find in some area of functionality.  You
> really should install software only for a specific reason.  Just
> throwing software at a problem isn't usually useful and creates the risk
> of introducing new variables.

Well, I sort'a kind'a mostly agree, ... but ... not entirely.  ;-)

So, I think *sometimes* it can be useful to do reinstalls ... notably of
relevant packages, and I'm typically also presuming these are all distro
provided, and current with distro (or one also still has, or obtains,
those same versioned packages from the distro).

E.g. ... can be fair bit of a shotgun approach, but let's say, for sake of
argument, one does an apt-get --purge remove ... of all the relevant
packages.  And then (re)installs them - same packages, same versions.
(different package management systems may, or may not (quite) have quite
the same capabilities.  In the case of apt[-get], remove, with the --purge
option, not only removes the package, but also removes any configuration
files for the package, whereas a mere remove would remove the package(s),
but leave their configuration files.  Also not sure, but I believe
apt[-get] also has reinstall option(s)/command - and not sure if that
might also support use with --purge or the like, to do a remove+purge+
(re)install in a single combined command).
So, anyway, let's say one does shotgun approach, purges (in the apt[-get]
--purge sense) a bunch of packages, then (re)installs them.  That might
tell one something - maybe it works (or does so after some configuration
bits), ... maybe it doesn't.  Maybe it's even worse after.  That might be
(semi-)useful information ... but it's not very granular, and doesn't tell
one particularly what one "fixed" and where (or broke, or broke worse, and
where, depending upon results).
But one can refine that further.  Rather than a bunch of packages at once,
how 'bout one package at a time, and retest after each?
Okay, now we're starting to get somewhere.  Still doesn't tell one
exactly "where", but narrows it down closer.
Let's refine further.  Now let's say, before removing *anything*, one creates
a nice fresh backup that includes at least *all* configuration files
that could at all possibly be relevant.  And from that, again,
proceed package-by-package, purge, (re)install, retest.  Now if/when one
gets to particular package, that, let's say "fixes" it after doing
that (possibly with bit 'o config maybe needed after (re)install),
now one has it narrowed down fair bit - to that package and its
configuration.  Again, if it's same package and version (and presuming
nobody/nothing did anything particularly funky/stupid, like do stuff outside
of distro packaging or that breaks or interferes with such), then at least
theoretically one would have it narrowed to the configuration file(s) of
that particular package.  But hey, we can refine further ... backed all the
older config files up freshly before purging anything, right?  Okay, continue
to refine - divide and conquer.  Should be able to narrow it to specific
configuration file(s) (notably between newer, and the earlier backed up),
and then should be able to continue to isolate to particular line(s)/item(s)
in specific configuration file(s).  Congratulations - you've found and
isolated quite precisely where the issue came from - if you made it that
far, got those results in thus isolating it.

"Of course" things could also go wrong - things may not go quite as
expected, so there may be unintended consequences of such a
purge/(re)install approach.  E.g. if something was somehow broken/altered
within a package ... whether someone (or something) did something stupid,
or such otherwise got altered/corrupted ... or if any of the underlying
presumptions may not be fully correct and true.  So it's not a 100%
sure-fire approach.  But, at least *sometimes* it can be useful.
And, *sometimes* it may get one to isolating, finding, and fixing the
issue quicker ... but absolutely not guaranteed to do so.

So, ... in (approximate) conclusion.  Relatively like Rick, I certainly
wouldn't recommend willy-nilly removing/purging and reinstalling a bunch
of packages, in general, to try and "fix" some issue - that's mostly too
broad of a shotgun approach, and even if it happens to manage to "fix"
the issue, it may leave negligible clue as to precisely what and where
was causing the issue (thus also risks it happening again if one has no
idea as to how the issues was caused to begin with).
But, more selectively and judiciously applied, and in (approximate)
step-wise fashion, and with relevant data backed up, it *can* be a
useful isolation/troubleshooting technique ... *sometimes* even faster (but
not necessarily so).  And also, no guarantees it will get one to the or a
"fix", and it quite possibly could also make things *worse*.  So, keeping
all that in mind, in at least *some* circumstances, it may be useful and
worth doing/trying/risking ... but too, in many(/most?) cases, there generally
will be better and more sure-fire ways to isolate the cause(s) of the  
issue(s).

> _Better_, this person in the Outer Richmond wants $15 for a Samsung
> ML-1865w B&W laser printer.  It does PCL5e-type printing and 1200x100
> dpi resolution, which is good.  Connectivity is USB or wireless.  No
> ethernet, but one can't be too picky for $15.  Footprint is 13.4" wide
> by 7.2" deep.  Weighs 9.2 lb.
> https://sfbay.craigslist.org/sfc/sys/d/san-francisco-samsung-ml-1865w-printer/6802988723.html

Sweet!  Nice find/hunting!  At a price like that, that brings ROI
down to mere *months*! - and nothin' but continued savings thereafter.
Also pretty dang reasonable size/weight for those more space constrained
(my all-in-one color laser is pretty dang heavy and has a fairly bulky -
but not too huge for me - sized footprint).