Re: DD bs=4M option on USB mem-stick creates false format

From	"Thomas Schmitt" <scdbackup@gmx.net>
Newsgroups	linux.debian.user
Subject	Re: DD bs=4M option on USB mem-stick creates false format
Date	2017-03-30 00:00 +0200
Message-ID	<tqtNf-4wn-3@gated-at.bofh.it> (permalink)
References	<tqso9-3FE-15@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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Hi,

kAt wrote:
> I am trying to find out
> what firmware works with this medium and what it really does.

It's a little computer which implements USB bus operation, and a subset
of the SCSI command protocol, and also manages the mapping from logical
addresses (LBA) to physical addresses.
What it does internally becomes mostly of interest if it cheats on you.
(Multiple block mapping and keyboard simulation are known.)

> I suspect the chips are the same memory chips one finds in a ddr/dram

Not at all. The memory technology is about whether they keep their
memory without electrical power supply
  https://en.wikipedia.org/wiki/Flash_memory
  https://en.wikipedia.org/wiki/Dynamic_random-access_memory

> using a USBstick as additional Ram.

... and a formatted 550 MB CD-RW as hard disk ? |:o

> I understand that xorriso was meant for writing cd/dvd mediums

Plus Blu-ray. Actually it coordinates ISO 9660 multi-session with writing
to various media and file types.
The boot topic is an add-on, mainly because IBM in ancient times
specified as "El Torito" that booting from CD is an add-on to ISO 9660.

> If a decompressed image of a system takes up 3Gb and you are using an
> 8Gb disk why is it not consistent that you can partition and format the
> rest of it?

Because on the first hand, optical media usually have no partition table
but some have a hardware backed table-of-content which lists tracks and
sessions.

On the second hand, a classical pure-BIOS isohybrid imposes no problem
to partition editors other than often the unusual partition start 0 of
the ISO 9660 partitioni causes a warning. (This can be changed to
block 64 by the xorriso feature of partition ofsset which writes a
second superblock and directory tree for ISO LBA 16 = disk LBA 64.)

On the third hand, Matthew Garrett (mjg) expanded the isohybrid layout
to EFI and even some Macs which expect a HFS+ filesystem with some
special files which are marked by "blessing".
This layout boots on a wide range of machines with x86 processor.
But it offends specifications and the software which more or less
implements those specifications.

> Why would live image makers vary so much in the way they do this?
> I think the vast majority of users are not really interested in the
> details but functionality,

The main functionality is to boot and to offer the installation features.
If the ISO image producers knew how large your USB stick is, then they
could add a partition with empty filesystem which fills up the stick.
But as we see, one may not even believe the size as printed on the
sales box.

Have a nice day :)

Thomas

Thread

DD bs=4M option on USB mem-stick creates false format kAt <giathnygeia@openmailbox.org> - 2017-03-26 19:40 +0200
  Re: DD bs=4M option on USB mem-stick creates false format Darac Marjal <mailinglist@darac.org.uk> - 2017-03-26 19:50 +0200
  Re: DD bs=4M option on USB mem-stick creates false format Richard Owlett <rowlett@cloud85.net> - 2017-03-26 20:00 +0200
  Re: DD bs=4M option on USB mem-stick creates false format kAt <giathnygeia@openmailbox.org> - 2017-03-26 20:10 +0200
  Re: DD bs=4M option on USB mem-stick creates false format "Thomas Schmitt" <scdbackup@gmx.net> - 2017-03-26 20:20 +0200
    Re: DD bs=4M option on USB mem-stick creates false format kAt <giathnygeia@openmailbox.org> - 2017-03-27 12:20 +0200
      Re: DD bs=4M option on USB mem-stick creates false format "Thomas Schmitt" <scdbackup@gmx.net> - 2017-03-27 14:20 +0200
        Re: DD bs=4M option on USB mem-stick creates false format "Thomas Schmitt" <scdbackup@gmx.net> - 2017-03-27 14:40 +0200
          Re: DD bs=4M option on USB mem-stick creates false format "Thomas Schmitt" <scdbackup@gmx.net> - 2017-03-28 12:20 +0200
            Re: DD bs=4M option on USB mem-stick creates false format Richard Owlett <rowlett@cloud85.net> - 2017-03-28 14:00 +0200
              Re: DD bs=4M option on USB mem-stick creates false format <tomas@tuxteam.de> - 2017-03-28 14:20 +0200
                Re: DD bs=4M option on USB mem-stick creates false format Richard Owlett <rowlett@cloud85.net> - 2017-03-28 15:50 +0200
                Re: DD bs=4M option on USB mem-stick creates false format <tomas@tuxteam.de> - 2017-03-28 15:50 +0200
                Re: DD bs=4M option on USB mem-stick creates false format "Thomas Schmitt" <scdbackup@gmx.net> - 2017-03-28 16:30 +0200
                Re: DD bs=4M option on USB mem-stick creates false format Richard Owlett <rowlett@cloud85.net> - 2017-03-28 17:40 +0200
                Re: DD bs=4M option on USB mem-stick creates false format "Thomas Schmitt" <scdbackup@gmx.net> - 2017-03-28 19:10 +0200
              Re: DD bs=4M option on USB mem-stick creates false format "Thomas Schmitt" <scdbackup@gmx.net> - 2017-03-28 14:20 +0200
                Re: DD bs=4M option on USB mem-stick creates false format <tomas@tuxteam.de> - 2017-03-28 14:20 +0200
                Re: DD bs=4M option on USB mem-stick creates false format Richard Owlett <rowlett@cloud85.net> - 2017-03-28 14:40 +0200
                Re: DD bs=4M option on USB mem-stick creates false format Richard Owlett <rowlett@cloud85.net> - 2017-03-28 15:20 +0200
            Re: DD bs=4M option on USB mem-stick creates false format songbird <songbird@anthive.com> - 2017-03-28 19:30 +0200
              Re: DD bs=4M option on USB mem-stick creates false format "Thomas Schmitt" <scdbackup@gmx.net> - 2017-03-28 20:40 +0200
                Re: DD bs=4M option on USB mem-stick creates false format songbird <songbird@anthive.com> - 2017-03-29 07:50 +0200
                Re: DD bs=4M option on USB mem-stick creates false format "Thomas Schmitt" <scdbackup@gmx.net> - 2017-03-29 10:30 +0200
                Re: DD bs=4M option on USB mem-stick creates false format "Thomas Schmitt" <scdbackup@gmx.net> - 2017-03-29 12:20 +0200
                Re: DD bs=4M option on USB mem-stick creates false format "Thomas Schmitt" <scdbackup@gmx.net> - 2017-03-29 12:40 +0200
            Re: DD bs=4M option on USB mem-stick creates false format kAt <giathnygeia@openmailbox.org> - 2017-03-29 00:50 +0200
              Re: DD bs=4M option on USB mem-stick creates false format songbird <songbird@anthive.com> - 2017-03-29 07:50 +0200
              Re: DD bs=4M option on USB mem-stick creates false format "Thomas Schmitt" <scdbackup@gmx.net> - 2017-03-29 10:20 +0200
                Re: DD bs=4M option on USB mem-stick creates false format kAt <giathnygeia@openmailbox.org> - 2017-03-29 22:30 +0200
                Re: DD bs=4M option on USB mem-stick creates false format "Thomas Schmitt" <scdbackup@gmx.net> - 2017-03-30 00:00 +0200
              Re: DD bs=4M option on USB mem-stick creates false format Curt <curty@free.fr> - 2017-03-29 16:40 +0200
                Re:Movie 'n Book recommendations by Curt kAt <giathnygeia@openmailbox.org> - 2017-03-29 22:10 +0200
                Re: Movie 'n Book recommendations by Curt Lisi Reisz <lisi.reisz@gmail.com> - 2017-03-29 23:40 +0200
                Re: Movie 'n Book recommendations by Curt kAt <giathnygeia@openmailbox.org> - 2017-03-30 20:10 +0200
                Re: Movie 'n Book recommendations by Curt Lisi Reisz <lisi.reisz@gmail.com> - 2017-03-30 20:20 +0200
                Re: Movie 'n Book recommendations by Curt Richard Owlett <rowlett@cloud85.net> - 2017-03-30 20:50 +0200
                Re: Movie 'n Book recommendations by Curt Catherine Gramze <rhiamom@mac.com> - 2017-03-30 20:30 +0200
                Re: Movie 'n Book recommendations by Curt Eike Lantzsch <zp6cge@gmx.net> - 2017-03-30 20:40 +0200
                Re: Movie 'n Book recommendations by Curt John Hasler <jhasler@newsguy.com> - 2017-03-30 21:30 +0200
                Re: Movie 'n Book recommendations by Curt Terence <terence.john@gmail.com> - 2017-03-30 22:00 +0200
                Re: Movie 'n Book recommendations by Curt Catherine Gramze <rhiamom@mac.com> - 2017-03-30 22:40 +0200
                Re: Movie 'n Book recommendations by Curt Lisi Reisz <lisi.reisz@gmail.com> - 2017-03-31 00:20 +0200
                Re: Movie 'n Book recommendations by Curt Catherine Gramze <rhiamom@mac.com> - 2017-03-31 01:30 +0200
                Re: Movie 'n Book recommendations by Curt Jonathan Dowland <jmtd@debian.org> - 2017-03-31 09:50 +0200
                Re: Movie 'n Book recommendations by Curt Terence <terence.john@gmail.com> - 2017-03-31 12:40 +0200
                OT: speaking of days (weeks, months, years, etc.)  (was: Re: Movie 'n Book recommendations by Curt) rhkramer@gmail.com - 2017-03-31 15:10 +0200
                Re: OT: speaking of days (weeks, months, years, etc.)  (was: Re: Movie 'n Book recommendations by Curt) Lisi Reisz <lisi.reisz@gmail.com> - 2017-03-31 15:40 +0200
                Re: OT: speaking of days (weeks, months, years, etc.)  (was: Re: Movie 'n Book recommendations by Curt) Greg Wooledge <wooledg@eeg.ccf.org> - 2017-03-31 15:50 +0200
                Re: OT: speaking of days (weeks, months, years, etc.)  (was: Re: Movie 'n Book recommendations by Curt) rhkramer@gmail.com - 2017-03-31 16:20 +0200
                Re: OT: speaking of days (weeks, months, years, etc.)  (was: Re: Movie 'n Book recommendations by Curt) Eike Lantzsch <zp6cge@gmx.net> - 2017-03-31 16:30 +0200
                Re: OT: speaking of days (weeks, months, years, etc.)  (was: Re:  Movie 'n Book recommendations by Curt) Curt <curty@free.fr> - 2017-03-31 18:00 +0200
                Re: OT: speaking of days (weeks, months, years, etc.) kAt <giathnygeia@openmailbox.org> - 2017-04-01 00:20 +0200
                Re: OT: speaking of days (weeks, months, years, etc.)  (was: Re: Movie 'n Book recommendations by Curt) rhkramer@gmail.com - 2017-03-31 16:20 +0200
                Re: OT: speaking of days (weeks, months, years, etc.)  (was: Re: Movie 'n Book recommendations by Curt) Lisi Reisz <lisi.reisz@gmail.com> - 2017-03-31 17:00 +0200
                Re: OT: speaking of days (weeks, months, years, etc.)  (was: Re:  Movie 'n Book recommendations by Curt) Liam O'Toole <liam.p.otoole@gmail.com> - 2017-04-01 19:20 +0200
                Re: OT: speaking of days (weeks, months, years, etc.)  (was: Re: Movie 'n Book recommendations by Curt) Lisi Reisz <lisi.reisz@gmail.com> - 2017-04-01 20:10 +0200
                Re: OT: speaking of days (weeks, months, years, etc.)  (was: Re:  Movie 'n Book recommendations by Curt) Liam O'Toole <liam.p.otoole@gmail.com> - 2017-04-01 21:30 +0200
                Re: OT: speaking of days (weeks, months, years, etc.) Peter Hillier-Brook <phb@hbsys.plus.com> - 2017-03-31 17:20 +0200
                Re: OT: speaking of days (weeks, months, years, etc.) kAt <giathnygeia@openmailbox.org> - 2017-04-01 00:20 +0200
                Re: OT: speaking of days (weeks, months, years, etc.) Lisi Reisz <lisi.reisz@gmail.com> - 2017-04-01 00:50 +0200
                Re: OT: speaking of days (weeks, months, years, etc.) GiaThnYgeia <GiaThnYgeia@openmailbox.org> - 2017-04-01 18:10 +0200
                Re: OT: speaking of days (weeks, months, years, etc.) Stefan Monnier <monnier@iro.umontreal.ca> - 2017-03-31 16:50 +0200
                Re: OT: speaking of days (weeks, months, years, etc.) Lisi Reisz <lisi.reisz@gmail.com> - 2017-03-31 17:00 +0200
                Re: OT: speaking of days (weeks, months, years, etc.) Eike Lantzsch <zp6cge@gmx.net> - 2017-03-31 17:10 +0200
                Re: OT: speaking of days (weeks, months, years, etc.) kAt <giathnygeia@openmailbox.org> - 2017-04-01 00:40 +0200
        Re: DD bs=4M option on USB mem-stick creates false format Pascal Hambourg <pascal@plouf.fr.eu.org> - 2017-03-27 21:00 +0200
          Re: DD bs=4M option on USB mem-stick creates false format "Thomas Schmitt" <scdbackup@gmx.net> - 2017-03-27 21:50 +0200
  Re: DD bs=4M option on USB mem-stick creates false format David Christensen <dpchrist@holgerdanske.com> - 2017-03-27 06:10 +0200
    Re: DD bs=4M option on USB mem-stick creates false format kAt <giathnygeia@openmailbox.org> - 2017-03-27 14:10 +0200
      Re: DD bs=4M option on USB mem-stick creates false format rhkramer@gmail.com - 2017-03-27 14:30 +0200
      Re: DD bs=4M option on USB mem-stick creates false format Greg Wooledge <wooledg@eeg.ccf.org> - 2017-03-27 14:40 +0200
        Re: DD bs=4M option on USB mem-stick creates false format "Thomas Schmitt" <scdbackup@gmx.net> - 2017-03-27 15:10 +0200
        Re: DD bs=4M option on USB mem-stick creates false format David Christensen <dpchrist@holgerdanske.com> - 2017-03-27 20:20 +0200
          Re: DD bs=4M option on USB mem-stick creates false format Pascal Hambourg <pascal@plouf.fr.eu.org> - 2017-03-28 00:00 +0200
      Re: DD bs=4M option on USB mem-stick creates false format David Christensen <dpchrist@holgerdanske.com> - 2017-03-27 19:40 +0200

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