grub2 confusion

[Michal Jaegermann]

On Fri, Oct 07, 2011 at 12:03:46PM +0200, Michael Schwendt wrote:
> On Thu, 6 Oct 2011 20:11:51 -0600, MJ (Michal) wrote:
> 
> > On Thu, Oct 06, 2011 at 05:05:06PM -0600, Eric Blake wrote:
> > > On 10/06/2011 05:01 PM, Michael Schwendt wrote:
> > > >>> you would not notice any troubles.
> > > >>
> > > >> Umm, yes you would.  That's not atomic, and risks leaving things in an
> > > >> inconsistent state.
> > > >>
> > > >> http://www.flamingspork.com/talks/2007/06/eat_my_data.odp
> > > >> http://www.pixelbeat.org/docs/unix_file_replacement.html
> > > >
> > > > cp -f ${grub_cfg}.new ${grub_cfg} ; rm -f ${grub_cfg}.new
> > > >
> > > > Better?
> > > 
> > > No.  cp is not atomic.
> > 
> > I think that in this particular case you are overdoing that concern.
> > These are small files and real writes are in blocks and not
> > characters.
> 
> Well, to defend Eric, it's okay to be pedantic in this case at a technical
> level. Sort of.

Well, yes.  But in the same posting you are qouting here I also
wrote how to fix grub2-mkconfig in a simple way while taking into
account those concerns.  AFAICS this is really a matter of filing a
bug report instead of long discussions on a mailing list.

I my opinion proposals of "drop a symlink" kind are really misguided
attempts to paper over the issue.  Some symlink may always reappear
for one reason or another and then we are back to a square one.

   Michal