Coda File System

Re: A few questions...

From: Stephen J. Turnbull <>
Date: Sat, 13 Nov 2004 13:33:23 +0900
>>>>> "redirecting" == redirecting decoy <> writes:

    redirecting> Currently, if I try to run venus as a normal user I
    redirecting> get this error message:

    redirecting> 17:33:23 CHILD: mount system call failed. Killing
    redirecting> parent

mount(2) is a privileged call.  You have to be root to do that.

It's true that you can set up /etc/fstab so that unprivileged users
can mount removable media and the like, but that is done by making
mount(1) suid root and having it execute the system call as root.

    redirecting> 2) What is the preferred method of shutting down
    redirecting> venus?

Depends on your system.  The generic method is "vutil shutdown", but
on many Linux distros, the rc script does extra work.  Eg, on Debian
you want to do "/etc/init.d/venus stop".

    redirecting> As it is now, when I kill venus on either of my
    redirecting> servers, I have to venus -init to restart it,
    redirecting> otherwise it turns into a zombie.

This is controlled by a parameter in /etc/coda/venus.conf, IIRC.

    redirecting> 6) How much can coda tolerate ?  I mean, can I use it
    redirecting> to do something like run www/mail/ftp services off
    redirecting> the Filesystem "fairly" reliably?  Or am I asking too
    redirecting> much...

That depends on what you're planning to do.  Eg, I wouldn't run
something like a wiki off a Coda file system---multiple writers means
conflicts.  Forget Zope!  But Coda + appropriate round-robin setups in
the DNS is quick & dirty way to get high availability for read-only
pages (assuming venus runs stably, of course).  Mail is discussed
fairly often; ISTR that maildir setups will probably work, but because
Coda is designed to run disconnected, it cannot assume locking can be
done reliably, so it doesn't try---forget mbox.  Anonymous FTP with
only admin users writing (including the owner of a user directory---
the important thing is one-write-access-at-a-time) will work, etc.

Caveat:  I haven't actually tried any of this, I'm just summarizing
what I recall from list discussions.

Institute of Policy and Planning Sciences
University of Tsukuba                    Tennodai 1-1-1 Tsukuba 305-8573 JAPAN
               Ask not how you can "do" free software business;
              ask what your business can "do for" free software.
Received on 2004-11-12 23:34:50