[Server-devel] Nepal Server Open Issues

[Greg Smith (gregmsmi)]

Hi Tony et al,

Great work this weekend! The Moodle static test pages are very helpful.

I updated the Apache spec/requirements section of the wiki
(http://wiki.laptop.org/go/Nepal:School_Server_Specification) with your
web directory examples. I also added the proposed wireless in school
network suggestion. Feel free to make any more edits or additions any
time.

I'm batching up a bunch of responses and comments going back to last
week.

On - 
JW> Yes.  We are hoping to get one including some critical new services
(activation and update) out in the next week.

Let us know when people should start testing the new XS image. 
Do you any info on planned changes or should we just read the diffs in
the GIT tree (http://dev.laptop.org/git)?

On -
JW> The network is the biggest headache right now.  Are you planning to
deploy in any schools larger than 150 students ?

Yes the Nepal deployment is > 150 (see Bryan's reply). Plan is for 2
school servers if that helps. Is there some way we can isolate the Xos
to create two smaller and presumably more stable Meshes? If we go with a
DHCP Manual MAC - IP assignment we can probably attach Xos to a given XS
at L3 via default gateway and routes but I'm not familiar with how the
Mesh builds adjacencies to segment or if it can be segmented in to two
Meshes. Any doc links appreciated.

Also, how can we get an active antenna ASAP? I think Tony requested one
but if there's somewhere I can buy with a credit card and ship it to
Tony or Nepal, I'm happy to do that.

Network reliability has already been flagged as a concern by the Nepal
team. I think we should have a "safe mode" which is essentially offline
from XS but with XO mesh (or not?) and pre-loaded activities. Please
comment on any known Mesh issues or suggest a query on the bug database
if you want us to look it up.

On -
JW> Focus on one of the first two.   I'm curious what you mean by
"BitFrost", cause the BitFrost document didn't really extend past the
laptop.   The current ID scheme (described in earlier mail to Martin) IS
the BitFrost ID scheme.

My fault for not RTFM on Bitfrost. I used it imprecisely to refer to a
user identity scheme overall. I saw your very helpful note to Martin. I
leave it to him to decide if that will allow Moodle to track identity
and therefore enable groups.

The easiest way I can see to track identity is to make the IP address =
the user. Here's a doc link showing how to do  that with DHCP in Fedora
(http://fedoraproject.org/wiki/Docs/Drafts/AdministrationGuide/Servers/D
HCP?highlight=%28dhcp%29). You may have to Yum down the DHCP server
itself if its not in the base Fedora install.

Can someone confirm if Moodle can use IP address for authentication and
user identity?

If so, we can write the Mac address in to the DHCP config and assign
each an IP address. Then that IP plus user name should get added to
MySQL DB and be used to control Moodle access. There's some scripting
needed to make that more efficient than copy and paste, but should be
doable.

On -
TP>
http://www.ibm.com/developerworks/blogs/page/InsideSystemStorage?entry=u
nderstanding_lamp_platform_for_web
Tony you do great work! Plus your blog is a lot better written and
formatted than my Wiki posts :-)

On - 
BB> # 1 thing is backup and reliability

Thanks for the direction! My next effort will be to comment on the
reliability write up at http://wiki.laptop.org/go/Nepal:Redundancy
following the heuristics defined. We also need to hear what's coming in
the next XS build and then decide if that covers backup or you need some
other solution.

On - 
BB> #2 Students need to be able to be able to "archive" their files to
the server once they run out of local space, or at least able to browse
the regular backup of their files to the server. This could conceivably
be done using Moodle.

What is the planned deployment build on the XO? I believe G1G1
production laptops crash when the HD fills up so we should watch for
that.

Aside from that, your description is different than what I expected. I
can see activities needing access shared storage on the XS. I can also
see students wanting to extend their storage there. I'm not sure that
they want to "browse" files on the XS. I think this area needs more
definition especially re: XO client side access to shared storage. We
also need to show a very stable network before we put a lot data (=BW)
on the XS which the activies or Xos in general need to access regularly.

On - 
BB>#3 Moodle
I think Martin is driving this area. Let me know how I can help. 

Nepal team - here are a few questions, suggestions and decisions needed:
1 - Need to decide ASAP if we will deploy the new XS image or the
current one. Also, please confirm if we have two XS boxes in the school
or one.

2 - I suggest that people try upgrading their XS to the latest image and
take notes on how its done. Even if we deploy OLPC_XS_150.iso it helps
to have docs on to re-image. We want to know what Nepal or user specific
content can be preserved. We may also want to upgrade modules one at a
time. Does anyone know of docs or best practices on upgrading whole
boxes or by components for LAMP servers?

3 - Need closure on SSO. Pending Martin's comments on the applicability
of the existing paradigm, you should pick a solution. Sounds like John W
suggests no user tracking or possibly one of the work arounds. 
See item 3 at this link for proposed workarounds:  
If it's a workaround we better clarify which right away. 
 
4 - Based on SSO decision you need to confirm what kind of Moodle
interface and services will be in phase 1. My main question is if we
will use Moodle to access activities.

5 - On the school network. Can you confirm if we can get 2 x router +
wireless Access points per XS? We need to flush out the failure cases
and the available HW will have a big effect on that. Let us know what HW
is in place. If ts just a matter of buying a few Linksys routers, I
think we can find a way to do that.

Sorry for the long post, and HTHs.

For anyone else on the list, we could use more people willing to build
an XS server and test out the Nepal design. See Tony's blog for step by
step instructions and let me know if you can help. If we provide solid
support to launch this pilot, we can build trust and get lots of great
feedback from a real school... 

Thanks,

Greg S