New mergemaster option -I, failsafe install files

[Jeremie Le Hen]

On Sun, May 10, 2009 at 09:54:42PM -0700, Doug Barton wrote:
> Jeremie Le Hen wrote:
> > Hi Doug,
> > 
> > As you may guess from my multiple emails, I'm in the process of
> > upgrading my jails :-).
> > 
> > Since I have one jail per service, a very few number of configuration
> > files are modified on each jail.  As most of user of FreeBSD I think,
> > I'm used to run "mergemaster -iU" to automate the process as much as
> > possible.  The problem with service jails (chapter 15.6.1 of the
> > handbook) is that / is read-only mounted on all jails, /etc /var /root
> > and a few other places being symlinks to /s, the private read-write
> > space of each jail.  Thus when mergemaster tries to update
> > /boot/devices.hints it fails and abort.
> 
> I think the way to solve this problem would be with an
> MM_PRE_COMPARE_SCRIPT that deletes /boot/device.hints (and any other
> relevant files) from the temproot. If they are not present in that
> directory when the comparison starts then it's a non-issue.

Actually, /boot belongs to the read/only nullfs mount, so it is not
possible to use MM_PRE_COMPARE_SCRIPT from the jail.  The only way to
handle this currently is to remove /boot from the jail template.

I'm Cc:ing -doc@ because chapter 15.6.1 of the handbook (service jails)
needs to be updated to remove /boot from the jail template "mroot".

Thanks.
Regards,
-- 
Jeremie Le Hen
< jeremie at le-hen dot org >< ttz at chchile dot org >