On Mon, Jun 1, 2015 at 12:37 PM, Pete Travis <lists@xxxxxxxxxxxxxx> wrote: > I would think that grub2 would boot el6 without chainloading, but I haven't > tested that... good catch, I'll look into it. A bz ticket would help make > sure the question doesn't fall off the radar, if you have time. Yes. Use /etc/grub.d/40_custom to create a simple menu entry that searches for the CentOS /boot volume by UUID, and then use the 'legacyconfigfile' command to point to that volume's /boot/grub/grub.conf. Ergo, GRUB2 can read GRUB1 configuration files. And then grub2-mkconfig to create a new (Fedora) grub.cfg that contains this menu entry. By default os-prober should find CentOS and create a generic menu entry for it. a.) This may not happen if CentOS uses LVM, and at the time of installation when grub.cfg was created, the CentOS root LV wasn't active. In this case os-prober doesn't find the installation. So you can make it active to create the generic menu entry which is useful as a template for the set root and search by UUID command mentioned above. b.) After making the 40_custom change you'll probably want to edit /etc/default/grub to add the GRUB_DISABLE_OS_PROBER=true line so you don't get superfluous CentOS boot entries. c.) The generic menu entry might work for some people as is, the problem is that since it doesn't point to the CentOS grub.conf, kernel updates don't affect this Fedora grub.cfg so it requires intervention to create a new grub.cfg in Fedora anytime a CentOS kernel update happens. Plus, it's a generic entry, you don't get the distro specific boot parameters. So for all of these reasons I prefer the use of configfile and legacyconfigfile (and there's also GRUB support to read syslinux/isolinux/extlinux configuration files). Sadly, grub2-mkconfig doesn't create menu entries using these commands by default so it's not the most user friendly thing. -- Chris Murphy -- users mailing list users@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines Have a question? Ask away: http://ask.fedoraproject.org
