Re: [RFC] server's statd and lockd will not sync after its nfslock restart

[Neil Brown <neilb@suse.de>]

On Thu, 17 Dec 2009 11:18:53 -0500
Chuck Lever <chuck.lever@oracle.com> wrote:

> Jeff Layton pointed out to me yesterday that Red Hat's nfslock script  
> unconditionally deletes sm-notify's pid file every time "service  
> nfslock start" is done, which effectively defeats sm-notify's reboot  
> detection.
> 
> sm-notify was written by a developer at SuSE.  SuSE Linux uses a tmpfs  
> for /var/run, but Red Hat uses permanent storage for this directory.   
> Thus on SuSE, the pid file gets deleted automatically by a reboot, but  
> on Red Hat, the pid file must be deleted "by hand" or reboot  
> notification never occurs.

Just to make sure the facts are straight:
 SuSE does not use tmpfs for /var/run (much as I personally think that
 would be a very sensible approach for both /var/run and /var/locks).
 It appears that Debian can use tmpfs for these, but doesn't by default.

 Both SuSE and Debian have boot time scripts that clean up /var/run and other
 directories.  They remove all non-directories other than /var/run/utmp.

If Redhat doesn't clean up /var/run at boot time, then I would think that is
very odd.  The files in there represent something that is running.  At boot,
nothing is running, so it should all be cleaned up.  Are you sure Redhat
doesn't clean out /var/run???

I just had a look at master.kernel.org (the only fedora machine I can think
of that I have access to) and in /etc/rc.d/rc.sysinit I find

    find /var/lock /var/run ! -type d -exec rm -f {} \;

So I'm thinking that if you just remove

        # Make sure locks are recovered
        rm -f /var/run/sm-notify.pid

from /etc/init.d/nfslock, then it will do the right thing.

NeilBrown