Re: Debian Derivative: Rescatux

[adrian15 <adrian15sgd@gmail.com>]

El 29/12/13 10:20, Paul Wise escribió:
> On Sun, Dec 29, 2013 at 1:04 PM, adrian15 wrote:
>>>> The third problem is that is not a tool to be used in a working
>>>> installation but from a live cd (it assumes no partition has been 
>>>> mounted). So not sure that it will be useful as a normal package.
>>> Live images are just normal installations
>>> that live on media that are
>>> read-only and possibly removable. I expect there will be zero issues
>>> or if there are some, they will be easy to fix.
> > Well, yes, I meant the other way round. A normal user in his Debian
> > installation trying to install Rescapp, downloading all these dependencies
> > packages and then nothing working as expected because not being in a live
> > system.
>
> My point was that there would be no reason for Rescapp to be broken on
> any system, live or not. I don't know how I would even write a program
> that wouldn't work when running off read-only media, especially since
> all live systems these days have a memory-only read-write layer above
> the read-only media. Could you explain the problems you would expect?

First of all sorry for taking so long to reply (I have re-rescued some 
texts from former email so that conversation makes sense).

Most of options present in Rescapp perform a rescue task. Usually the 
first step for this task is to detect affected partitions.

If you are dealing with GNU/Linux you will search for /etc/issue file. 
If you are dealing with Windows system you search for 
c:\windows\system\sam or equivalent.

I hope you get the idea.

In order to detect these partition I loop them based on /proc/partitions 
information so that I mount, examine and umount them.

The problem comes, after the detection phase, when the user selects the 
partitions which it wants to recover/fix.

The recover procedure mounts the partition, fixes it by copying files or 
running commands on a chroot, and then umounts it.

This last recover procedure can only work successfully if the selected 
partition is initially not mounted. It's not that it won't work in most 
of the cases but that I have not the total security of this double mount 
being a problem. Not to say that some of the options like fsck might 
need the partition to be completely umounted.

What I mean is that:

* On a GNU/Linux Live CD such as Rescatux which it is based on Debian 
Live I can enforce that USB automount or initial mount of partitions is 
not done at all.

* On an installed GNU/Linux system I have to deal or cope with the 
different scenarios where automount might have already mounted an usb 
hard disk that the final user wants to fix. That means probably warning 
the final user that he needs to make sure the partition that needs to be 
fixed needs to be unmounted. And, well, you know that usually means to 
quit the file manager windows that were using it.)


boot-repair, which it's another tool somehow similar to Rescapp deals 
with this situation by killing all the caja, nautilus, dolphin and other 
file manager processes. Then it unmounts the partition if it's mounted 
and then performs its tasks.


I hope you get the idea. I am relunctant on people using Rescapp outside 
Rescatux because there would be some variables (Broad sense meaning) 
that I won't control.

At the same time I know that there are people that would like to use an 
installed version of Rescatux/Rescapp for performing its rescue tasks 
for third people without having to use it as a live cd ( 
http://www.supergrubdisk.org/forum/index.php?topic=813.0 ).

I suppose I wouldn't have to be worried about these issues. If someone 
wants to fix a computer it will probably use Rescatux directly and not 
use an installed Debian system and install rescapp package over it.

And if someone installs rescapp on an installed Debian system he 
probably knows what he's doing.

OFFTOPIC: Although not needed in my case and probably not a good idea in 
most of the cases this thread has made me to think about a new deb 
package switch, option, rule of no dependency, etc. E.g. when you would 
want to install rescapp:

"You cannot install this package because it cannot coexist with 
debian-installed-system package".

What's debian-installed-system ? A package that only exists in Debian 
installations. This package does not exist in Debian Live.


adrian15
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