Coda File System

Re: replicated servers

From: Phil Nelson <phil_at_cs.wwu.edu>
Date: Thu, 7 Apr 2005 16:43:32 -0700
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On Thursday 07 April 2005 14:44, Patrick Walsh wrote:
>        First, suppose I have a realms file like this:
>
> realm1          coda1 coda2
> realm2          coda2

This is a misunderstanding of a realm.   A realm is a collection of coda 
servers with a SCM and other servers.    So the realms file should never have 
the same server listed in two different realms.   

Replication in a single coda server collection (realm) works within the 
servers in the realm.

Each realm talks about a different coda server collection.     You don't 
access the replica by trying a new realm.  The replica is "invisible" so that
if one server in the realm is down, you can still get the replicated volume 
from the server that is up and you get the same information from a replica.
(Server-server conflicts are when the replicas have conflicts and you use the 
repair tool to get the replicated volumes to be the same again.)

You can ask where a file/directory is located and it will list all the servers 
on which the file/directory is located.

     cfs whereis /coda/realm/path/to/object

- --Phil

- -- 
Phil Nelson                       NetBSD: http://www.netbsd.org
e-mail: phil@cs.wwu.edu           Coda: http://www.coda.cs.cmu.edu
http://www.cs.wwu.edu/nelson 
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Received on 2005-04-07 19:44:43