Re: Putting It All On a Stick
On Thu, 31 Dec 2015 10:23:10 -0500
Steve Matzura <sm@noisynotes.com> wrote:
> Thomas, just dd the file? That really works? I've got to try this.
> I've heard of this being the way to do things, but find it hard to
> understand how it could work. I suppose the boot loaders know what to
> do with ISO images.
>
No, it's the very opposite of knowing where things go. The dd command
is a very simple, completely unintelligent copier. But an ISO file is
an image, literally every byte stored on some medium being scraped up
in order, with the intention that it is laid down byte-for-byte starting
at location zero on some other medium. An ISO contains bootloader,
partition table (where used), unused space, the whole lot. What you end
up with is a precise copy of the original (as long as the write medium
is at least as large as the read medium), and dd is the simplest way to
achieve that.
Its only real drawback is that it copies every single byte, used or
not, and other copiers can be quicker if they ignore unused areas. Of
course, to do this, they have to know what is unused, and there is an
obvious risk of error. dd doesn't miss anything, you just need a book
to read while it works.
--
Joe
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