[ovs-dev] [PATCH] packaging: Do not automatically restart user-space on upgrade

[Ben Pfaff]

On Mon, Jan 16, 2012 at 02:10:40PM -0800, Ansis Atteka wrote:
> I can alter the postinst behavior from 1.4 and up branches to the following:
> 
> > if upgrade-from-pre-1.4-ovs to 1.4+-ovs then
> >   throw a warning that kernel module needs to be reloaded so not
> > restarting user space
> > else
> >   do only userspace restart and use old kernel module
> > fi

This sounds reasonable to me.

> > The warning seems too severe.  Userspace should be able to cooperate
> > with newer and older kernel modules (since 1.4), so restarting or
> > loading the new kernel module isn't strictly necessary.
> 
> When upgrading from 1.3 to 1.4 it looks like 1.4 user-space can't talk
> with older 1.3 kernel-space. So kernel reload is necessary for
> this particular
> upgrade combination.

Yes, I agree.

> > In general I think we'd prefer to restart OVS automatically whenever
> > the new package is installed, except when that is not going to work
> > because we are upgrading from a pre-1.4 version.  Looking at the issue
> > you cited, the problem was an upgrade from a 1.3 version of OVS to a
> > later version.  It would make sense to me, in that case, to print this
> > kind of warning and avoid restarting OVS.  You could use "dpkg
> > --compare-versions" to figure out when it is appropriate.
> 
> I agree that most of users would like the packaging scripts to trigger
> the restart automatically for them. But I also think it would be preferable
> to do the upgrade exactly the same way across all platforms (e.g. Xenserver
> and RH). AFAIK these two platforms do not trigger automatic restart as
> of now.

Yes, I agree that consistency is valuable.  But I think that we should
first figure out what behavior is best (as we're doing now, in this
thread) and then use that behavior on all the platforms.

Thank you for looking at this.

Ben.