Re: FAQ rm backup section outdated

[Garreau, Alexandre]

Le 05/03/2018 à 21h46, Bob Proulx a écrit :
> Garreau, Alexandre wrote:
>> at some point it suggests recover is packaged and right away
>> installable under Debian while it’s not packaged anymore since
>> Wheezy [1] (currently oldoldstable), moreover it seems its webpage
>> [2], that is the second reference of the section, is a dead link.
>
> Alas it seems there is only the archive.org version now.
>
>   
> https://web.archive.org/web/20080725005349/http://recover.sourceforge.net/linux/recover/

The following thread explains why it has been removed from debian and
gives link to more stable and robust tools to achieve the same thing
(debugfs from e2fsprogs)
<https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=735858>

>> The third [3], too, except I couldn't find it neither in my system at
>> the aforementioned path [4], without forgetting to note that it suggests
>> reading it with less, while with it being gzipped it should be read with
>> zless.
>
> That depends upon your system.  On my system less defaults to knowing
> how to read gzip'd files without needing zless for it.

Oh, I didn’t checked at first because I thought that would need a
less=zless alias or symlink, or similar, and I didn’t thought to it as
being common, but in fact under Debian less is by default only less and
not zless, or at least it doesn’t know how to read gzip'd files.

>> I managed with apt-file to find its translations are still
>> packaged in the packages doc-linux-fr-text and doc-linux-pl, but
>> couldn't manage to find their original version, which is sad since from
>> what I read in the french version, it seems to be really well written
>> and maybe even quite useful for other filesystems than ext2.
>
> Once again archive.org is an invaluable resource.
>
>   
> https://web.archive.org/web/20051220103138/http://tldp.org:80/HOWTO/Ext2fs-Undeletion.html
>
> However that is specific to ext2.  If you are not using an ext2 file
> system then it will be of little help for you.

I found interesting informations that are more general and of good
advice, like how to remount read-only (afaik under ext3-4 the metadata
are zeroed but not the content, that would be too long and costful and
useless especially if the file is big right?), which stays useful for
using testdisk thereafter.

Anyhow I think the english version should have been be packaged anyway,
and still can’t understand how french and polish version did remain, while
japanese and hungarian versions didn’t.

>> The fivth [5] is dead too, while since then it seems to have been
>> packaged for Debian, even Wheezy nodaways, through backports, and at
>
> A copy of the reference page is:
>
>   
> https://web.archive.org/web/20131105155135/http://developer.berlios.de/projects/ext4magic
>
> But of course the code release is not available from there.

It still is in Debian and still installable however.

>> The last [6] is also dead, probably due to the move of Gentoo wiki to a
>> subdomain of its [7], yet seemingly without the page in question [8].
>
>   
> https://web.archive.org/web/20081007100003/http://www.gentoo-wiki.com/HOWTO_Move_Files_to_a_Trash
>
> I will work through this entry and give it a refresh.  Given the
> current state of the world what would you say there?

Oh, I thought it would recommand to use gvfs-trash, as I sometimes do,
but yet it would require more dependencies to be installed so I get this
way.

>> Everything of this appears quite frustrating to me, as I always only
>> knew testdisk and photorec (which I often heard cited yet I didn't see
>> mentioned there), and seeing this link I hoped to easily find some
>> simpler (cli instead of tui for instance) or easier (higher-level)
>> utility.
>
> First I can only say sorry for your loss.  Because I know if you had
> not lost something you wanted back that you would not have gone to the
> trouble of this research and then writing here.  However depending
> upon the system if a file has been removed then it is likely lost
> without a backup of it.

I lost 700Gio (but mostly movies) of data a half dozen of years ago,
with testdisk running for 3 days, then several shellscripts written for
the occasion, to sort (using mv, read, and file) the more quickly (only
some weeks), what have been found (of course unnammed, and sometimes
only partial files), I think I recovered 16Gio, but only really
partially some really important stuff I wanted (like the package manager
I wrote in shellscript at the time, using absolutely nothing other than
bash builtins except mv, ln and for some other syscall-dependant stuff,
with package-user method from LFS (one user per package files set,
really dirty), with DMD (now Shepherd) instead of SysV as an init
system, and the totality of recipes for all GNU packages + what’s needed
to built the whole OS from scratch) from a system I compiled myself
(without X thought) from scratch and I used for daily use for at least 6
months (probably among the most productive I knew).

> What file system type held the files now lost?  To be recoverable it
> would need to be a file system that does not overwrite the data when
> the file is removed.

ext4. But the loss wasn’t due to rm, it was because at the time, after
lfs I was recommanded gentoo, so I installed it, lacked size at some
time, rebooted on a liveusb to resize the main (700G) partition, and
since the computer was near dying, it of course did shutdown during the
2-hours-long partition shrink. I never ever did try again gentoo since
then. And Debian became my only way to go.

Since I still sometimes do installs or teach its existence to people
(otherwise only acknowledged about ubuntu), I sometimes get questions
about how to unrm stuff, and since of course I do, sometimes, small
mistakes or change my mind, I’m still a bit interested at what’s
possible and what’s not.