[Sugar-devel] [support-gang] XO 4 reimage

[James Cameron]

G'day Christine,

Thanks for asking.

The green dots will have gaps.  Part of upgrading from XO-1.  Your
photograph is fine.

The inconsistent connections are impossible to fix entirely, but you
can reduce how often it happens:

1.  if testing alone, turn off automatic power management in Sugar, My
Settings, Power, before turning on the next XO-4,

(otherwise an XO-4 will be asleep when the next XO-4 connects, and
they can choose different network id or channel, and neglect to show
the new icon,)

2.  rather than let the XO-4 choose the ad-hoc wireless channel,
choose it youself by clicking on the icon, then click on Join,

(otherwise an XO-4 may choose another channel than the other XO-4 in
the room),

3.  use a wireless access point instead of ad-hoc wireless, especially
if there are more than 14 XO-4 laptops,

(so that there is never any ambiguity about the network name or
channel #12808, and to avoid a wireless connection hang #12763),

4.  when a class of XO-4 seems to be split into two separate networks,
pick the smallest subset and turn every single one of them off, wait
for them all to be off, then turn them on.

(because the way that Sugar chooses an ad-hoc wireless network is by
name only, and if there are two networks with the same name the system
can't tell which one is which, and just joins one of them ... happened
to me on Saturday with just five XO-4),

5.  turn off any non-essential wireless access points, like mobile
phone internet sharing.

(because each of them is transmitting a beacon, or replying to probe
requests, and this can make it impossible for the classroom
environment to sustain ad-hoc networks).

Hope that helps!  I can guide you on how to prove if any of the above
makes a difference, but it's usually easier to just do it.

--

Technical References:

#12808, (ad-hoc networks are partitioned),
http://dev.laptop.org/ticket/12808

#12767, (also reduced by item 1 above),
http://dev.laptop.org/ticket/12767

#12763, (ad-hoc fails with more than 14 laptops).
http://dev.laptop.org/ticket/12763

On Sun, Oct 18, 2015 at 11:59:59AM +0000, Christine Murakami wrote:
> Hi all. I sure do appreciate your continued involvement with the support gang. I don't participate much, but am always grateful when I get enthusiastic answers to my questions.
> 
> I'm trying to reimage a bunch of XO 4's to the newest build and am struggling. I'm getting the software from http://wiki.laptop.org/go/Release_notes/13.2.5 and have tried different flash drives to rule out flash drive error, have tried downloading it a second time to see if the first copy have been corrupted, and have tried the same flash drive on different XOs. My next step is to buy a new flash drive and try again, but before I make a trip to the store, I thought I'd check in to see if these are known problems.
> 
> Here are my questions:
> 1- when it starts the reimage process and runs the little green dots across the screen, the top 5 or so lines are really interrupted. Not red blocks, but many stretches of blank spaces. This isn't normal for the XO 1's I've reimaged - and I've reimaged hundreds - but I'm inexperienced with the XO4. Is this normal? (Once it gets past the first couple of lines, it's all solid green.)
> 
> 2- Once I reimage, I get inconsistent connection to other XO's. Sometimes they will see one another, and then at other times they stop seeing the people they used to see. Some machines will see one or two but not all XO's in the room, while other pairs find each other but not the rest of the class. I didn't know if these inconsistencies are because of a bad reimage or not, which is why I've tried so many different things.  (They do see and connect to wireless networks, the Internet in a Box server I have, and the Ad Hoc networks.)
> 
> I know we have a lot of distributed knowledge out there, so let me know if there is a better release file I can find somewhere or if you have ideas about whether this is as good as it gets. I've also attached a photo of what the reimage looks like.
> 
> Thanks!!
> Christine Murakami
> 
> 

-- 
James Cameron
http://quozl.linux.org.au/