[fedora-arm] Some comments on bconoboy's trimslice images

[David A. Marlin]

Richard W.M. Jones wrote:
> On Fri, Apr 27, 2012 at 09:42:22AM -0500, David A. Marlin wrote:
>   
>> Richard W.M. Jones wrote:
>>     
>>> In general pretty good - they work well.  However there are a few
>>> problems I encountered:
>>>
>>> (1) There's no source for the boot scripts.  I think you should put
>>> the source along side the binaries, in /boot/uboot.  I ended up using
>>> 'strings' and reconstructing them.
>>>       
>> Agreed, the source for the script should be added.
>>     
>>> (2) The sda boot script works fine, however the mmc boot script fails.
>>> 'fatload mmc 0:1 ...' should be 'fatload mmc 1:1 ...' (in both places).
>>>       
>> It worked as provided for me (fatload mmc 0:1).  Could this be
>> device dependent?
>>     
>
> Possibly.  I replaced the supplied no-brand micro SD card (4G) because
> it failed, with a branded Samsung 32GB card.  I've no idea if this
> would change the numbering.
>
>   
Ah, I see the difference.  I used the external (front) SDCard slot, and 
not the internal micro-SD.  I think this image was intended for the 
external (front) slot.

>>> (3) If you have both images installed, then it boots one of them at
>>> random, because it boots from 'root=LABEL=rootfs' which picks one of
>>> the labelled root devices at random.
>>>
>>> This is not a completely stupid configuration: you need to do this if
>>> you're booting from a USB key and copying the mmc image to the
>>> internal drive.  At some point you'll have a trimslice with both the
>>> sda image and the mmc image.  Probably better to use UUIDs, or to have
>>> different labels.
>>>       
>> I think he was going for consistency across images (change as little
>> as possible) and to support copying the image to an internal drive,
>> as you mentioned.  Would using UUIDs work in this scenario?
>>     
>
> If the UUIDs are different, or changed to be different
> (tune2fs -U ...)
>
>   
>> If so,
>> what would need to be done (if anything) besides transferring the
>> image (via 'dd')?
>>     
>
> The problem is I was using the sda image for my external (sda) drive,
> and the mmc image for my internal drive.  The main issue was confusion
> -- why rebooting would randomly choose a different root device.
>   
Yes, that would be confusing, and not desirable.  :(
>   
>> I'm working on creating disk images using lorax/anaconda, and have
>> modeled much of the configuration from Brendan's scripts, so any
>> tips are appreciated.
>>     
>
> Standard advice is to use UUIDs instead of labels or (worst of all)
> device paths.  However if we're copying images around at all, then
> there's the danger of having duplicate UUIDs which is really bad.
>
> I wonder if the normal Fedora live CD generates a new random UUID
> after resizing the minimized image?  It must do.
>   
I don't know how that works, but since it does I think it would be good 
to leverage that approach (whatever it is).

d.marlin
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