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

[Bill Bogstad]

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.

Thanks,
Bill Bogstad