Coda File System

Re: Some question

From: <>
Date: Mon, 29 Mar 1999 10:54:17 -0500
Hi Simone, said:
| These are my question :
| - how can I do to know if the two server are communicating ? I tried
| to copy 1,5Gb on data in /coda, but after a 1Gb the copy fail, so I
| have this doubt :
| - if I have two server with each 1Gb, I have a total of 2Gb, or the
| second server take a copy of scm data ?

This all depends on how you have created your volumes. A volume can bre 
replicated over multiple servers, or on a single server. f.i. If the 
volume storage group database looks like this:

E00000100 scm-server
E00000101 other-server
E00000102 scm-server other-server

Then a volume on only `scm-server' can be created using:
	createvol_rep new_volume E00000100 /vicepa

A volume on both `scm-server' and `other-server' can be created using:
	createvol_rep new_volume E00000102 /vicepa

The new volume can be mounted anywhere in /coda using:
	cfs mkm somedir new_volume

When volumes are replicated across multiple servers, every server will
have an identical copy of the volume-data. So with `single replicated' 
volumes you would get 2 GB, with `doubly replicated' volumes there will 
be 1 GB available, but then you can lose either server and still have 
full access to the data.

| Last question : when I setup venus with venus-setup, in the list of
| servers I must list only scm servers, right ? But what does this mean
| ? What is the mean to use two scm server ? If I have a scm server on
| my machine, said, what appen if I do venus-setup
|, 20000 ?

You do not have to list only the scm-server, every server knows about
the locations of all volumes within the same administrative domain. So 
you can list any servers.

However, when you specify servers in different administrative domains, 
they will not know about which volumes the `other group' has. So you'll 
only see the volumes and files associated with the server you happened 
to connect to first. Which might be a different one everytime you 
restart venus, and this can easily lead to very confusing things in the

Received on 1999-03-29 10:56:57