(Illustration by Gaich Muramatsu)
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 intrusion. When an inconsistency is detected CODA could do something like the following: 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 conflict. 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 files. 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. Matt -- Gary Thomas <gary_at_chez-thomas To: CODA <codalist_at_TELEMANN.coda.cs.cmu.edu> .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