Coda File System

Re: FAQ: Is Coda ready for use?

From: Lionix <>
Date: Sun, 30 Nov 2003 18:37:13 +0100
That depends of what you mean by "ready for use".
Will give you the answer i know.
Hope I will be able to answer all one day !

>I know this is a FAQ, but one year ago, the homepage said the same and I
>won't believe it's still so.
The web site did not changed too much last years...

>Currently we are running an AFS installion on nearly 30 machines with
>Linux Debian as root fs. But last week I picked off the server and all
>was down. This event brought on a discussion about availability and afs
>doesn't have any mechanisms for high availability. Does coda has an
>Achilles' heel like afs the volume server?
Volume root is critical too in coda,  but you can avoid freezing the 
whole set of machines by write-replicate this volume. You will find the 
process in the last weeks mails...
A conflict on this volume would critical so you'll have to only use it 
as configuration purpose and prevent user from writing on it.
And everything works weel when the SCM server is down ! :o)

>We plan to use coda on the whole faculty to provide user home dirs and
>data. This would be nearly 200 machines and 1000 users. Is coda ready for
>such a usage or would we run in trouble?
Wow ! I've seen a 30 machines configuration stuff in the ml two years 
ago but i've never heard about so big deployement of coda-fs.
Guess you'll have to define multiple realms.

>I read in any documentation coda respects the unix permission of files.
>Is this correct?
No, you can't use chown / chmod to manage permissions, they are provided 
by the ACL and unix permission are not used anymore . Even if a file is 
root:root 600, everybody can read the file if directory is ACL-readable..
User have to authentificate to against the auth2 server ( primary the 
scm, replicated / balanced on other servers in case it would be down ) 
via the clog command. There is some pam written to automaticate the process.

>With afs we have the problem secure files in a public
>directory like /etc/shadow aren't save. Everyone can access them and we
>could restrict the access to them without inhibit access to the whole
ACL are set for a directory... not for a file.

>How does coda match with kerberos? I read some articles in the archive
>which tell about problems. Are there still problems?
I've never tested the pam_kerberos written by Mr Popov.
But i'm sure it works well as he use it !

>Is it possible to deactivate the cache on the client machines at runtime?
I would say no.. caching mecanism is a full part of the coda client ( 
venus ).
Why would you like to do such a thing ??? You can define the size of the 
cache in conf file.
Cache size must me at least the size of the bigest file you'll have to 

>Does coda need a process in userspace to access the coda fs?
If you mean a process started by the user the reponse is no.
Coda must be started by the root, init script stuff.

FS-Realm (newbee?) Administrator
Hundreds hours of work but so powerful !
Received on 2003-11-30 12:45:26