On Wednesday, February 17, 2016 10:03:04 AM Rick Stevens wrote:

> On 02/16/2016 09:19 PM, Mike Wright wrote:

> > On 02/16/2016 08:15 AM, Chris Murphy wrote:

> >> At the GRUB menu, type

> >>

> >> pager=1

> >> set

> >>

> >> Look for variable 'prefix=' this will be drive, partition, and path, to

> >> the GRUB directory where its cfg and modules are found.

> >

> > All right Chris!

> >

> >

> > So apparently grub.cfg is ?compiled? into some other secret location

> > know only to the bootloader. I have the sinking feeling I have to run

> > some grub2 magic spell to get the modified boot file into wherever it

> > goes but am loathe to try anything. The reason I have a stripped down

> > grub.cfg is because the last one generated for me was pushing 200K and

> > the boot lines in each stanza had, so help me, nineteen swap files

> > included in each one.

> >

grub2 uses the file /boot/grub2/grub.cfg by default. This file does get rebuilt by kernel updates, and by running /sbin/grub2-mkconfig

> > Now the question:

> >

> > Is there a command that will take my simplified grub.cfg and install it

> > without modifying it in any way and leave me with a bootable system?

> > (please please please say yes).

>

> I've never used it, but I suspect grub-menulst2cfg may do what you

> want. It claims to "Convert a configuration file from GRUB 0.xx to GRUB

> 2.xx format". If you're going to continue to tinker in this way, you

> really have to read up on grub2:

>

> http://www.gnu.org/software/grub/manual/grub.html

>

> I agree it's convoluted and confusing and I'm not a fan (just like I'm

> not a fan of systemd or journald), but that's what you're stuck with.

>

> Most of the config info you may need to change is in /etc/default/grub.

> The scripts that generate the menu entries are in /etc/grub.d

> (particularly 10_linux and possibly 40_custom). The final config created

> by grub2-mkconfig generally ends up in /boot/grub2/grub.cfg.

>

If you remove the file /etc/grub.d/30_osprober, then grub2-mkconfig will not look for other operating systems to add to the config file, but will only add the kernels for the current OS. Then if you have a simple chainloader as the initial config that points to each OS, each OS will only have its on entries in its grub.cfg.

--

Lester M Petrie

Bldg 5700, Room O305

Oak Ridge National Laboratory

Phone 865-574-5259, Email petrielmjr@ornl.gov