any drawbacks to using copy-nand and save-nand to install XO images

[Bryan Berry]

thanks Michael, this is really helpful

On Thu, 2008-03-27 at 15:23 -0400, Michael Stone wrote:
> Bryan,
> 
> Several weeks ago, I was asked to do reverse engineer an image created via
> save-nand for another client and I discovered many "unexpected differences"
> that had crept into the image as a result of lack of detailed knowledge of what
> happens during the first boot and lack of established procedures for comparing
> images.
> 
> Some of the unintended changes that I observed included:
> 
>   * /home/olpc/.devkey.html  has been created and specialized.
>   * Change in /etc/hosts
>   * /security/state/var/lib/dbus/machine-id set.
> 
>   * LANG="es_AR.UTF-8"  setting in /home/olpc/.i18n
>   * /security/state/etc/timezone set to GMT
> 
>   * Enabling XFree86-Misc extension in /etc/X11/xorg.conf
>   * Removing the ServerFlags section in /etc/X11/xorg.conf
>   * Removing control #32 in /etc/alsa/asound.state
> 
>   * 26M of data in /home/olpc/.sugar/default/data/
>   * Extra cached data in /home/olpc/.sugar/default/*
>   * Datastore exceptions recorded in the Journal log.
>   * ssh(d) configuration and moduli in /security/state
>   * LANG="C" setting in /security/state/etc/sysconfig/i18n 
> 
> The point of this laundry list is simply that, while save-nand may be
> convenient for simple purposes, the changes made by our boot configuration
> process causes it to generate very "ragged" results. A much better strategy is
> to reflash an XO, boot it off of external media (like a USB key), make changes
> to the NAND, then save-nand, thus avoiding the first-boot configuration junk.
> 
> Alternately, one can refer to the suggestions in an email I sent earlier this
> week:
> 
>   http://lists.laptop.org/pipermail/devel/2008-March/012130.html
> 
> for some more other approaches.
> 
> Best,
> 
> Michael