[Server-devel] Three levels of access

[Tony Pearson]

Martin,
You bring up some good points.

By "Wifi" I meant a simple hub that has both wired connections for the XS, 
as well as WiFi for teachers/guest/administrators to have unfiltered 
access to the internet.  The one I have is a D-Link 4-port hub.  This 
would also allow the teachers/administrators to have a shared network 
printer if appropriate.  The XS would be directly wired into this hub, not 
wireless, I agree.

I agree the XO, in and of itself, is a great learning tool.  I envision 
three levels here:

(a) XO only.  Teacher has an XO, students all have XO, and they are able 
to mesh on their own without any active antenna.  Is that true?  I have 
only
one XO, so no idea how meshing works.  Teachers maintain their own lesson 
plans on their own XO machines and push them out to their students.

I suggest the "buddy system" for files.  Any files that a student wants to 
keep, he shares with a fellow student, and and vice versa.  In the event a 
student has a problem with their laptop, the files they shared with others 
will be on other XO laptops, and can be copied back.    This is the logic 
behind "LOCKSS" (Lots of Copies Keeps Stuff Safe) --- I am not suggesting 
the use of this FOSS software, per se, but rather the concept can be done 
between students.  Here's a video.

http://hurstassociates.blogspot.com/2007/10/videos-on-lockss-lots-of-copies-keeps.html

Alternatively, students learn to save their work on USB memory sticks. 
These are getting cheaper and cheaper every year, and like you have your 
own XO, you can have your own memory stick, personalized on a keychain for 
example.  Many of us at IBM have one on our keyring or attached to our 
employee badge, to share files with clients, to act as our 
digital-briefcase to take stuff to work on at home, etc.

(b) Students have XO, Teacher has XO and access to a WEP-protected WiFi 
hub.  This would allow the teacher to download activities, digital
content and such, and do "manual filtering" (only content he/she deemed 
age-appropriate would be something she could offer to the rest of his/her 
class).
It would allow teachers to collaborate with other teachers, guests, and 
administrators, share lesson plans with each other, etc.  Students can 
continue to communicate over the mesh, with each other as above.  If there 
is a centralized "Library Server", the teacher can access it, download 
specific content and send out to the students over mesh.  Students that 
are looking for specific content could make a request to the teacher to 
get it on their behalf.

If the teacher wants to protect his/her own lesson plans, student records, 
etc.  he/she can upload to Google Docs, or one of the many free services 
that lets people have a 1GB or so of space to store things remotely.

(c) Students/teacher have XO, XS has active antenna and filtered, cached 
content for high-speed access, downloads of ebooks and activities, etc.
Students would have an enriched experience available to them, in addition 
to activities on their own XO, have the option to explore and download 
digital content, surf the web, send email to students or mentors in other 
places, etc.  Teachers would have access to moodle, and students can 
access moodle lesson plans.  Students and teachers would have access to 
Library server content.

The suggestion that we could back up student XO home directories to the XS 
machine is not bad.  Worst case, it is only 500MB (space available per XO) 
times 200 students, so 100GB disk capacity.  We could probably make a 
"Backup My Data" page in moodle that uploads the /home directory to the XS 
server.  This could be activated by the student, or scheduled to happen 
once a day, once a week, etc.

Alternatively, with students having access to the web, they could backup 
their files to Google Docs or other external service.  In the event that 
their laptop broke, they could download the files onto a fellow student's 
XO and share the XO until repairs are complete.

Everybody I know has lost work in progress at some point.  It is painful, 
and reminds us to save our work and take backups more often.  This is a 
lesson in life, and kids can learn it early.  I have found that sometimes 
losing something means starting from scratch with a fresh perspective, and 
often I have much better second version as a result.

While all three levels are better than what students have today in most 
schools, one could argue that each successive level provides benefits, 
obviously at a cost, but without sacrificing dropping down to lower levels 
during a time of outage.  Teachers should be able to teach without moodle, 
access to the internet, or LIbrary server content.  I agree we do not want 
to set up artificial dependencies.

As I mentioned on the topic of redundancy, you can figure out 
single-points-of-failure, determine the impact of their failure, and then 
decide what to do about it.  This could all be part of the teacher 
training process.  Teach teachers how to operate at all three levels, and 
let them be able to adjust as appropriate to the current conditions.

--- Tony





Tony Pearson
Senior Storage Consultant, IBM System Storage?
Telephone: +1 520-799-4309 |  tie 321-4309 |  Cell: +1 520 990-8669
email: tpearson at us.ibm.com |  GSA: http://tucgsa.ibm.com/~tpearson
Blog: http://www.ibm.com/developerworks/blogs/page/InsideSystemStorage 
AKA: 990tony Paravane, eightbar specialist 


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