[sf-lug] debian vs ubuntu question

[Michael Paoli]

> From: "Rick Moen" <rick at linuxmafia.com>
> Subject: Re: [sf-lug] debian vs ubuntu question
> Date: Fri, 15 Feb 2019 22:46:02 -0800

> Quoting Jim Stockford (jim.stockford at gmail.com):
>
>> Does the current release of Debian have
>> none
>> some
>> all
>> of the problems in Ubuntu 18.04
>> ?
>
> Please pardon a small jest in the formatting (but for a serious answer):
>
>        I
>      tend
>     to think
>    this is an
> 'iceberg question'.

Yep, I'm inclined to agree (or nose under the camel's tent, or something
like that).

> Which is to say, you're of course asking something you're interested in
> finding out about, but your question is based on assumptions that are
> best examined, to find out whether perhaps you are trying to solve the
> wrong problem -- in short, that the interesting stuff is below the
> surface.

Yes, ... not to mention questions (or at least initial such) being
pretty dang broad and potentially ambiguous ... and also nothing
stated about the reason/objective of the question, or what was trying to
be determined.

> I would guess that you're assuming that your recent problem with the
> wireless driver owed to some defect in Ubuntu Linux 18.04 LTS, and

I suppose I might've guessed that too, in the somewhat broader list
context and recent postings ... but, alternatively, I took the posting
as relatively standalone, and responded to it as it was.

> thus are wondering whether you should distro-hop to something else.
> Thing is, though, that this assumption seems really unlikely.  I really,
> really doubt that your Ubuntu installation's wireless configuration
> spontaneously broke, and doubt that a bug in Ubuntu caused the breakage.

Hmmm, yes, more list context ... again I took it more as standalone.
Including relevant context in posting(s) generally helps - folks might
better interpret what one is after or one's objectives, etc., and might
also well avoid going down the "wrong" (or an unintended) path.

> Unfortunately, now that you've shipped your laptop back to its vendor to
> have them do an OS reinstallation, you'll never be able to figure out
> who or what bollixed your wireless installation.  So, that's now

Sure - can still be determined.  Did an entire full image backup before
shipping the laptop off, right?  Right?  So, can always (re)use that
full image backup at one's leisure at any reasonably convenient time
in future to troubleshoot the original issue(s).

> officially a dead question.  My concern on your behalf going forwards
> is making sure you won't need to repeatedly ship your laptop across the
> country just to have the vendor reinstall it.

Hmmm, didn't ZaReason include DVD (or CD) of the distro you had them
originally install, so you could reinstall from that?  I know that
some years back when I bought a ZaReason laptop, they did include
DVD of the distro I had them install.
I believe also their support forum(s) might be quite to highly
useful ... but I don't have particular experience with that, so
don't know for sure.

> Ordinarily, I'd advise users 'Dude, just keep an installable image of
> your distro around on the shelf, know how to use it, and be prepared if
> necessary to reinstall.'  Obviously, you chose this time to have the

Yup, and hopefully(/presumably?) ZaReason provided that?

> vendor do it, instead, but wouldn't it be nice to make a snapshot of
> the freshly installed system, the moment you get it back?  I would

Yes ... when I received my laptop I'd purchased from ZaReason, one of the
very first things I did was create a full image backup of exactly what
they'd installed on the drive.  Basically I wanted that as a "reference"
copy - if ever I might find any issue(s) between my preferred distro and
the hardware, if ZaReason had it working with same distro on same hardware,
I might want that "reference" copy to compare or isolate/fix any issue
I might be having (never ended up needing/using it for that, but a
"good to have" for such purpose(s) ... "just in case").  Likewise such
a backup of the original could also be handy if one ever wanted to do
a clean (re)install to that point.

> earnestly recommend you do that, as cheap insurance.  (If you'd done
> that before, you'd have been able to avoid needing to ship the hardware
> across the country.  See my point?)

Yep, ... and disk is cheap these days ... can also wipe (null out) the
unused space first, then it would also compress very efficiently.

Oh, and presuming that they provided you DVD or the like, one could
generally boot and run that "live", to see if same issue(s) (e.g.
Wi-Fi) are present in that scenario ... or if that works fine when
booted that way.  (Yet another useful reference point / test).

> Here's what you do:  Get yourself whatever live Linux distro you're
> comfortable with.  (Whatever you like.) Get yourself a nice large USB
> external drive at least as capacious as your Linux partition (I assume
> there's only one) on your Linux laptop.  Once you have your laptop back,
> boot the live distro (from optical disk or flash drive).  Plug in the
> external USB drive.  Figure out what device nodes the laptop hard drive
> and the external USB drive are.  Use 'dd' to do a bitwise copy of
> the laptop hard drive to the external USB drive.  You're done.

Yep, ... I'd add compression to that though, and probably also null
out the unused filesystem space too.  So basic procedure I'd typically
use:
o boot from recovery media
o mount the nominal drive(s) filesystems rw
o for each filesystem, create a temporary file (e.g. with mktemp) on
   each filesystem, fill it with nulls (e.g.
   # cat /dev/zero > /path/to/temporary/file
   ) and then once that filesystem fills up, remove the temp file
o for any nominal swap, note label(s)/UUIDs, overwrite it with nulls,
   then reinitialize the swap and set with same type, label(s), UUIDs, etc.
o umount all the nominal filesystems, if/as applicable, deactivate LVM
   (# vgchange -a n volume_group_name), mdraid, etc. - essentially anything
   at all using the nominal drive(s) in any way.
o then make your compressed image backups of them - can also always
   do compression or tighter compression later (tightest compression
   might take quite a while), e.g.:
   # dd if=/dev/sda | xz -9 > /path/on/mounted/backup/media/sda.xz

Using something like the above, the resultant size of the file is
comparatively small relative to the source image ... nice side effect
of that is one can often store several or even many such images,
without space being a big issue.

> You now have a pristine safety copy, verbatim (stored on ice) of your
> laptop's entire contents.  I'm skipping over details, but a LUG meeting
> can help you.  (To do it with whooshing graphical programs instead of dd,
> use something like Clonezilla Live.)

Yep, backups, restore images, etc. - all good things.  :-)

And ... original question ... Debian, or Ubuntu ...
really depends what the objectives are.  I didn't see anything in
particular about that.  If it's merely getting Wi-Fi working,
that should be highly doable (or at least equally so), with either.