Kubuntu won't boot

[Ralf Mardorf]

On Tue, 27 Jul 2021 18:25:21 -0700, rikona wrote:
>[...]
>
>By changing the boot order I was able to do a "try it" boot from a
>Kubuntu CD, and I can see all the disks [within permission limits]. So
>far this runs OK as well, but I can't run the many pgms I had set up on
>the box, and likely not enough space to do that either [indexed search
>pgm is massive]. 
>
>I never did a backup, since it was running so well, so that is the
>FIRST thing I need to do but can't figure out how to get around the
>permission problems.

Hi,

you can backup all Linux partitions, at least those using the ext file
systems, by a simple copy command with root privileges

sudo cp -ai source target

the "a" option does copy everything, even attributes. The "i" option is
not needed, I'm just in favour of it.

To save disk space or to backup on an alien files system that doesn't
support permissions, attributes, characters, name length, file length
etc.

sudo tar -czf target source

note, only very ancient versions of Linux tar do not preserve
attributes. Instead of "z" you might want to use another compression.

This is the backup everything, in an absolutely secure way approach.
I'm used to it, for me it unfortunately takes around 12 hours, to just
backup important operating systems and important data, updating
everything would take way longer. Using something to sync would be way
faster, but it's to risky for my taste. I don't trust my skills on how
to use sync software.

>I have a few TB of data, on multiple disks, so a
>large backup is needed.  I normally use grsync, but it is refusing re
>permissions - can I get that to back up all the disks WITHOUT the
>permission problems, or do I have to wait until the box is running
>normally to get everything? Is there a better way to fix permissions
>and back up everything now?

A very common default user ID is 1000, live Linux tend to use another
user ID by default. However, this shouldn't matter for backups, just
backup with root privileges and preserve the original privileges. I
don't know how to do this with rsync, let alone grsync, but cp and tar
as described above are idiotproof, excepted of the _globbing_ pitfall.

The main globbing pitfall in short:

The * does not recognise all items. Hidden items, those starting with a
dot are ignored, but only for the parent. IOW * does recognize the item
   foo   , but not   .foo   , but it does recognise the item   foo/bar
and also   foo/.bar  .

>[...]All suggestions much appreciated... [even the "don't bother me"
>ones] :-) 

Using a Live Ubuntu take a look at log files, especially of the display
manager and xorg first. You even can take a look at the binary systemd
log files by using the    string    command, without the need to do
anything more complicated.

Regards,
Ralf