Coda File System

Re: Realms and machine names

From: Alan Tam <>
Date: Thu, 10 Feb 2005 06:16:10 +0800

Ivan Popov wrote:

>Hi Alan!
>On Thu, Feb 10, 2005 at 04:10:49AM +0800, Alan Tam wrote:
>>I have 2 volumes, one for development data and one for production data, 
>>and for effciency reasons, development data is stored in a development 
>>machine, and vice versa.
>If I understand you correctly and you believe that running a Coda server
>and a Coda client on the same machine is efficient - then you make a mistake.
>Coda is designed as a distributed filesystem, based on a model
>"few well-connected trusted servers, many unreliably connected,
>hardly trustable clients".
>It does not work well (though it works) with a client and a server
>on the same host.
I don't think it is very efficiently, but is probably the best we can do 
if we want the data to be accessed mainly on one machine and sometimes 
somewhere else. Am I correct? If NFS authentication support is better, I 
would have solved it very early.

>>Should I have 2 realms, or just 1? 2 realms 
>>because it sounds more natural to have something like /coda/dev for 
>>development and /code/prod for production data. 1 realm because it 
>>sounds wierd to "clog myname_at_dev".
>The path component present directly in /coda is essentially
>an administration domain. If you want to administer your production data
>totally independently of the development one - then use two realms.
>It would possibly double your administration work.
>I guess you'd rather keep administration as low as possible and use
>one realm...
I think I understand the concern.

>>Machine Name
>>Upon vice-setup, you have detected a machine name for the server, most 
>>probably by the "hostname" command or equivalent. But I don't like it, 
>>as this domain name is only for public access, and hence coda traffic 
>>shan't pass through it, but using the internal IP, hence another domain, 
>Using multihomed machines is tricky, I did not tried it, so can not
>tell anything of value. Anyway, you probably know that you should not try
>to use and "localhost"...
I think nobody would try to use localhost as hostname. But won't my 
situation be common somehow?

Two machines are on a "VPN", using unroutable IP to communicate (say, But they do own public IP, and services like apache 
would depend on the hostname. Hence the domain coda guessed would 
probably refer to some public IP (like, Of course we 
won't expect to be able to login via port 2432. Then 
shan't we be able to tell coda to simply treat the machines as 
and regardless of their other IP addresses?

Received on 2005-02-09 17:18:46