[Server-devel] help with small/first world XS deployment issues requested

[Morgan Collett]

On Sun, Oct 19, 2008 at 08:36, Bill Bogstad <bogstad at pobox.com> wrote:
> There are a number of  XO deployments possible in the Boston metro
> area sometime next spring.  My understanding is that OLPC does NOT
> want to run these deployments, but is interested in having them happen
> so there are deployments local to the Cambridge office for test
> purposes.  As a result, the local XO users group (OLPC_Boston) has
> been asked to help out.  As my background is in system administration,
> I offered to look into possible XS server deployments at the same
> time.  Even though I've been on server-devel since June; I'm still not
> sure to what extent an XS would be useful in these circumstances.
>
> As I see it, at this point an XS provides:
>
> 1. XO backup service (ds-backup)
> 2. Activation service? (probably not needed since XOs will be G1G1)
> 3. Support for > 20 networked XOs (ejabberd?)
> 4. Moodle server (not clear what this means in terms of funcionallity)
>
> Is that correct?  Is much going to change by January?  For a
> deployment of say 20-30 XOs in one location, does it even make sense
> to have an XS?
>
> Another issue is that reusing available resources (pre-existing
> wired/wireless hardware, dhcp/dns/web proxy/filtering services) would
> be very helpful.  Even if  pre-existing services are inferior to what
> an XS might provide, for political reasons in a small deployment, it
> is probably better fit into a framework with which local IT
> personnel are comfortable.  Unfortunately, my impression is that the
> current XS images are somewhat brittle in terms of assuming they
> control all of the networking services and as well as requiring
> specific IP numbering of various interfaces, control of DNS/DHCP/NAT
> routing/etc.
>
> I understand  the need to provide turn-key software for locations
> where there isn't anyone who understands networking.  However, I find
> myself in the situation where even though I know about netmasks, DNS A
> records, etc.; I have no idea how much of the higher level
> infrastructure on the XS requires leaving things as they are.  For
> example, can I have an XS with a single Ethernet interface?  I think I
> saw something in a config file somewhere that suggested this (doing
> DHCP on the Internet facing interface), but I can't find any mention
> of this anywhere on the wiki.  What if I want DHCP/DNS to be handled
> by something other then the XS, but do what the other services? Given
> the rapid pace of development, it's hard to tell from the wiki pages
> what works/used to work/was never implemented/is an idea for the
> future/etc.
>
> I apologize if the above is confused/confusing.  Unfortunately, that's
> the way I feel at this point.  I've got this big ball of string I'm
> trying to untangle and I have no idea where to start.  Any suggestions
> how to get a handle on this would be greatly appreciated.

For such a small setup you might not need everything the XS provides,
but you would still benefit from running ejabberd somewhere. You can
build it from source with the required OLPC patches:
http://wiki.laptop.org/go/Installing_ejabberd

I'm going to have a go at producing updated Ubuntu packages for this
ejabberd setup soon.

Regards
Morgan