Coda File System

General comment about CODA. Re: Fixing inconsistencies

From: Matthew R Welland <>
Date: Fri, 11 Oct 2002 08:49:39 -0400
A couple years ago I gave CODA a try and got it to work reasonably well.
This kind of problem - difficult to repair inconsistencies - was what
caused me to decide not to use CODA. I have a suggestion that might make
the end users experience of dealing with the inevitable occasionally
inconsistency less painful.

First: if this has been proposed before and rejected please forgive the

When an inconsistency is detected CODA could do something like the

1. Make the inconsistent file listable but neither readable or writeable
(this file could possibly be the version as it was on the server before the

2. For each possible version of the file create a new file in the same
directory with a naming scheme such as
<originalname>.host_where_modified.uniquenumber where the
host_where_modified portion can help the end user choose which copy to keep
and the uniquenumber prevents collisions in the case of multiple
inconsistencies over time and the end user did not remove the extraneous

3. Allow CODA to keep running! Having the filesystem become unavailable due
to some lock file being inconsistent is not fun. Use some standard
mechanism to notify the end user that there is a problem. What does nfs use
when a server goes down?

I found the CODA repair process to be very difficult to comprehend and it
didn't (at the time) work very reliability. The suggested process would be
understandable to almost anyone in my opinion.


                      Gary Thomas                                                                                                      
                      <gary_at_chez-thomas        To:       CODA <>                                      
                      .org>                    cc:                                                                                     
                                               Subject:  Fixing inconsistencies                                                        
                      10/11/02 07:26 AM                                                                                                

My local system has an inconsistency, but I can't get "repair"
to fix it (or it seems, even try):

    19:11:01 Local inconsistent object at
/coda/fpw/users/gary/.netscape/history.dat, please check!

    repair > beginrepair /coda/fpw/users/gary/.netscape/history.dat
    Could not allocate new repvol: Object not in conflict
    beginrepair failed.

I've also seen a different error from "repair" - something about
being out of directory entries (sorry, but I've lost that message).

Any help gratefully accepted.
Received on 2002-10-11 08:53:47