On Tue, Jul 26, 2022 at 8:23 PM Tim via users <users@lists.fedoraproject.org> wrote:
On Tue, 2022-07-26 at 14:39 +0000, Chris Murphy wrote:
> Do you think a graphical rescue environment would be helpful in
> troubleshooting system problems?

For some situations/people, yes.  I think you need a bare-bones command
line to get back control of a borked system.  But an additional
graphical option could be useful for those who need to point and click
a few bad settings back into normality.

> Do you think a graphical rescue environment using volatile storage,
> would be useful?

There's merits in being able to test things knowing that nothing you do
will make permanent changes, so you can go through your options to fix
something one after another until you find the right one, without
making things worse in the meantime.

There's also times when you need to boot into a simplified system and
make changes that will stick.

But if everything is non-volatile in your rescue environment, how would
you actually make any change that fixes a borked system?

A someone who is prepared to use bare-bones comand-line, the GUI should
provide the capabilities you get from a rescue kernel to mount
filesystems and use chroot.

Before all the Windows drives were encrypted, I have often booted a "dead"
Windows system with linux to copy a user's important files to an external drive
before giving the Windows box back to IT, who just restored the corporate standard
Windows image and did updates.


> Do you think a mechanism for system snapshots and rollbacks would be
> useful in troubleshooting system problems?

They never did any good on other OSs (for me, at least).  The undo you
needed to do was always in the middle of a set of changes.

There are so many interconnected things on modern OSs that it's very
difficult to remove a slab of things and not create a new problem.

System's borked, we'll roll back to how it was three days ago and still
working.  But what about all the work I've done since then?  Sorry,
that's all going to get trashed.  You can do it again.  No, I can't.

I used to work in a group with many Apple systems.  Every user had a
USB disk set up for Time Machine and the cost was more than justified
by the number of times it was used to recover from accidental deletions
of work that would take days to reproduce.
 

I'm not just talking about user data, documents you've written, etc.  A
person's work can be things that they were doing with the system.

When I look at backup management software, I give up in dispair.  It
works in that "go back several days" mentality.  It's hard to get back
the one thing you need.  Most system borks seem to be that you made a
goof (or it did) about three steps back, the fix is to work on that
goof, and not undo all the other things you did after it that wereSome very minimal data collection
perfectly fine.

It's exactly the same issue with wanting to undo one thing in the
middle of a word processor doc, or artwork in a graphic program.  The
undos/redos are all time-sequential, and not confineable to a specific
area of the data.

There are applications that allow you to maintain a record of your workflow
and then replay it.

I use a remote-sensing GUI called SNAP from the European Space Agency
which has a parallel command-line tool.  You can use the GUI to develop
a workflow and then use a (GUI) tool to re-create the workflow as a graph
with parameters to apply the same workflow to many files in batch
mode.  It is very helpful if you break the workflow into small steps
and check the results as you go.  The batch processing can be moved to
a server, and takes advantage of high-end hardware (many CPU's
and GPU's).

The ability to convert a GUI workflow to a batch script is important
for "reproducible research", and very helpful when troubleshooting bugs.
NASA has adapted the ESA GUI to some of their remote-sensing
systems as "SeaDAS".

--
George N. White III