[colug-432] creating sparse disk images

[Chris Punches]

You don't need a sparse file.  And you're telling dd to copy the whole disk
and that's what it's doing.  It's a 16GB card.  If you had partitions you
would refer to them as /dev/sdc{1..4}

To make an iso file from a directory you want to use something like

`mkisofs -o ${ISO_PATH} ${DIRECTORY}`

Keep in mind you still have no bootloader.  You'll want to install one if
you want to actually boot from that disk.  Grub2 is nice.

-C

On Mon, Nov 12, 2018 at 5:41 PM Roberto C. Sánchez <roberto at connexer.com>
wrote:

> On Mon, Nov 12, 2018 at 07:02:25PM -0300, Rick Hornsby wrote:
> >    A normal RaspberryPi image from Raspian is ~1.5GB as a zip, and as
> far as
> >    I can tell, around or about 4GB when expanded and burned to an SD
> card.
> >    I’m having a hard time taking the SD card and creating a sparse image
> from
> >    it. I think “sparse” is what I want — I burned the image to a 16GB SD
> card
> >    made some changes and then tried to use dd to create an image of the
> >    modified card, and no matter what I do I’m always ending up with a
> 16GB
> >    image file. The changes I made include installing a couple of
> packages, a
> >    couple of python modules, and setting up some python scripts to run
> as a
> >    service on boot. Nothing major.
> >    I’ve tried to run zerofree on the card (to ensure the free space is
> all
> >    0x00), and then specifying ‘conv=sparse’ to dd but it made no
> difference.
> >    I tried making the image on Linux and Mac. dd seems to be very
> similar on
> >    both.
> >    # dd if=/dev/sdc of=/tmp/sd_card.img conv=sparse
>
> It has been some time since I had to do something like this, but after
> creating the image with dd, you need you use something like rsync or
> qemu-img to turn the image into a proper sparse file.  I have used both
> and either one should do what you need.
>
> --
> Roberto C. Sánchez
> http://people.connexer.com/~roberto
> http://www.connexer.com
> _______________________________________________
> colug-432 mailing list
> colug-432 at colug.net
> http://lists.colug.net/mailman/listinfo/colug-432
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.colug.net/pipermail/colug-432/attachments/20181112/d9f93cd0/attachment.html