[Olpc-open] RE: [mass storage] Is it possible to substitute flash?

[Ivan Krstić]

I'm going to answer several e-mails in this thread at once, starting
with David's:

David Gelkin wrote:
> The actual machine will be for no better word a dumb terminal if I'm 
> not mistaken? Just a method for connecting to the net and accessing 
> the data on it.

You're entirely mistaken; these machines are not dumb terminals in any
sense of the term. They have the computing power of standard laptops
from around 2000 -- the mobile Pentium II PE Dixon 80524, released in
1999, was the first mobile Pentium chip capable of reaching 400 MHz.
There's nothing but the incredible software bloat and obesity that our
industry has fallen prey to, that would make you think these machines
aren't intended for standalone operation.

To clear this up: these machines are *absolutely* intended to run
serverless. The reason we're putting such an emphasis on the mesh work
is precisely because we are not making the assumption that an Internet
connection or a storage server are available, although we are also
working hard to make sure that in many places, they are.


Xavier Alvarez wrote:
> For example: there IS going to be a server, what if not? will the 
> activity still work? Will the software need to go in a special 
> server-less mode? How will that impact in the overall usability of 
> the software, etc.

In the *general* case, software is not allowed to rely on the existence
of a school server.

> Or more mundane: how will the kid browse his backups? a-la *nix? or a
>  more user-friendly way integrated into Sugar?

Backups will be fully integrated with our information platform, which
means they'll be reachable in searches, and browsable through the journal.

> Will things be (again) automagically uploaded to the server to free 
> space?

Subject to certain constraints, yes.


Brian Deyo wrote:
> Why involve a school server to do backups when a 512mb SD card would
> work just as well?

The school server is used to provide Internet connectivity and the
requisite routing and/or IPv4 tunneling, in addition to serving as an
upstream backup trickle cache. It is possible that a laptop can be used
to carry out some of these functions in a smaller school, but not the
large ones.


David Gelkin wrote:
> IF any RAID solution will/could be used etc....  Namely due to the 
> fact I want to be involved in this project and 2, my own company can 
> submit a tender as preferred data recovery vendor globally, which 
> will be required eventually as hard drives have a tendency to fail. 
> And if an entire school is dependent on this data then I believe this
>  is where I can help, and specialize in my own field, in a pro-active
>  way.

There are no current plans to do RAID nor data recovery. Part of the
reason is that, while the servers will use some of their hard drive
capacity to act as a first backup tier, their key backup role is as a
cache that trickles backups to a storage farm upstream, such that a loss
of a server's drive is nothing but a trivial inconvenience. My goal is
to be able to offer countries around 1-2GB of upstream backup storage
per child at no cost; we'll see what'll come of that.

-- 
Ivan Krstić <krstic at solarsail.hcs.harvard.edu> | GPG: 0x147C722D