Coda File System

Coda for high-latency web mirroring

From: Robert Schumann <>
Date: Fri, 18 Nov 2005 12:57:44 +0000
I'm new to Coda, and new to distributed file systems in general, but I 
have a particular problem to solve which I would appreciate some advice on.

I am trying to set up a dynamic web mirror in the USA of a server in 
Zambia.  Let me untangle that.  Zambia is connected to the internet by a 
(high-latency and highly bottlenecked) satellite connection.  The 
website I am interested in would benefit from input from international 
users as well as Zambians, so I would like to make page-loading times 
reasonable for both groups.  By "dynamic web mirror" I mean that the 
content must be editable in real time since the site is running a wiki; 
writing won't happen terribly often but when it does I would like to 
avoid locking/inconsistency problems.  Disconnected operation is not 
going to happen much.

The people in the worst situation would be Zambians connected by 
different satellite providers than my server, who would have to endure 
RTT of 0.5s.

I believe coda, or perhaps openafs, is a solution to this problem but 
haven't delved deep enough into the documentation yet to find out (it's 
a daunting task!).  The solution I was considering was (a) placing the 
wiki data files on server which is running a coda server, 
and (b) running coda client on  Split DNS allows us 
to direct Zambian users to, and everybody else to the 
other server.

My checklist for this sort of application is
 * easy configurability (I tremble when confronted with Kerberos...)
 * minimal custom hacks
 * good security, but not overwhelming (ideally the webserver should be 
able to use files transparently)
 * requiring minimal bandwidth/minimal communication between and
 * preferably not too much root access required ( is 
running on donated server space)

The server is running Ubuntu Breezy and has the coda 
kernel module installed, but Ubuntu does not include venus in their 
distro.  The server is running RHEL as far as I know.

Any thoughts?

Received on 2005-11-18 08:00:52