Re: Some help with dd backing up into an iso

["Thomas Schmitt" <scdbackup@gmx.net>]

Hi,

i quoted man bzip2:
> >  As  with  compression, supplying no filenames causes decompression from
> >  standard input to standard output."

GiaThnYgeia wrote:
> ...aka screen dump?

If the standard output of bzip2 is not connected to the standard input
of another process or redirected to a file, then i'd call that a
terminal flood. Ugly text salad which may even change display settings of
your terminal window.

Standard input, standard output, and standard error output are three i/o
channels which every process on a Unix-like system has. Connecting them
to other i/o channels or redirecting them to files is a fundamental
gesture of shell programming. (Yes, the shell is a programming language,
although we often only execute single command lines.)


> > In what state is "imagefile" now ? Compressed ? Uncompressed ? Ashes ?

> Now it is at the state of being all thrown to trashcan [...]
> a new project will begin sometime next week ....

Maybe you are giving up too fast.


> I think it was that dreadful Calamares installer that came with this sid
> distro that locks onto the disk and prevents ovewriting.

I deem this unlikely. Your Linux was up and had control. Our problem
is not about overwriting but about finding a directory path under which
we can read the files of the USB stick partition.

> But the usb was so hard locked that gparted would erase its partition,

So you interspersed some other experiments ? That might be entertaining
but also confusing.


> > is it reported as two lines:

> No it is all connected line [...]

> > The reason why i ask is that i wonder from where xorriso has this
> > strange two-line path.  It would be explainable if you had given it to
> > xorriso command "-map".

> So are you saying the problem may lie in the name length that xorriso
> can't handle?

No. The name length should not be an obstacle until it reaches limits
of the X/Open system specification (255 characters per name, 1024 per path).

The problem is rather that xorriso gets to see a file path which does
not lead to an existing file. Either this name stems from the program
arguments of the run (i.e. is given after -map) or it stems from
following a symbolic link, which tells a wrong target path.
In the first case, the operator i(i.e. you) is to blame. In the second
case, some automat installed confusing links.


> the question I have is if this is ....part1 where is the other part/s?

"part" shall mean "partition". I just wanted to keep the name short.


> > New approach to get to a mount point of the stick:

> xorriso : UPDATE : 116500 files added in 28 seconds
> xorriso : FAILURE : Cannot open as source directory: '/media/user/sid/lost+found'
> ...
> xorriso : aborting : -abort_on 'FAILURE' encountered 'FAILURE'

We got some progress now.
The new problem is the fact that xorriso (and possibly other user
processes, too) cannot read the content of
  /media/user/sid/lost+found

So why does this file make trouble ? IIRC, it is a directory which
holds files that were found orphaned during filesystem checks.
Please report the output of

  ls -ld /media/user/sid/lost+found

(I will have to investigate why xorriso tells no further reason for
 being unable to read the directory's file list.)

------------------------------------------------------------------

Whatever, this is a local filesystem problem which we may try to
circumvent by omitting the offending file object.

   xorriso \
   -for_backup \
   -outdev usb_part1.iso \
   -not_paths /media/user/sid/lost+found -- \
   -map /media/user/sid /

The xorriso command -not_paths takes one or more file paths which then
get excluded from the backup. The word "--" marks the end of this path list,
so that the next word "-map" is then interpreted as next xorriso command.

Let's see how far we will get with this try.

If more unreadable "lost+found" directories show up, you may ban the
name from being backed up when found under any path:

   xorriso \
   -for_backup \
   -outdev usb_part1.iso \
   -not_leaf lost+found \
   -map /media/user/sid /

Other than -not_paths, -not_leaf takes exactly one parameter. So no end
makr "--" is necessary.


Have a nice day :)

Thomas