On 05/22/2015 05:15 PM, Konstantin Olchanski wrote:
> On Fri, May 22, 2015 at 01:43:08PM -0700, ToddAndMargo wrote:
>>
>> After installing the above, the boot order came up with the
>> two rescue modes on top.  Would you please correct this?
>>
>
> This is a feature of grub2. In grub1, the order was specified manually
> in grub.conf. In grub2, the order is magically created by a mess of bash
> scripts. When installing a new kernel, it magically runs
> some magic commands to make itself the default kernel to boot. None of this
> is documented anywhere.
>
> If you want sane booting, switch to syslinux.
>

Hi Konstantin,

I have been working on a direct install Xfce Fedora 21 flash
drive.  I had to tweak the /boot/grub2/grub.cfg to get it
to boot off of all machine.  (Which it does, unlike Live
USB -- faster too).

In FC21's Grub.cfg, the "menuentry" are all appear in order
on the boot screen.  And, the "rescue" appears at the bottom.

Is the problem I noticed, a EL7 issue?  I logged into the
SL7 hard drive (that won't boot) with my Live CD and took
a peek at grub.cfg, and that is the way they were written.

And YIKES!  A Boo-boo in grub.cfg.  Look at this:

menuentry 'Scientific Linux 7.1 Rescue 95621d90ac5d4ae8a262fd52ed537a16 
(3.10.0-229.1.2.el7.x86_64)' --class fedora --class gnu-linux --class 
gnu --class os --unrestricted $menuentry_id_option 
'gnulinux-3.10.0-229.1.2.el7.x86_64-advanced-562d91f4-7086-451e-abc1-870f59bf3c41' 
{
....systemd.debug
}

	initrd16 /initramfs-0-rescue-95621d90ac5d4ae8a262fd52ed537a16.img
^^^^^^^^stray line that should have been above the "}" bracket ^^^^^^^

menuentry 'Scientific Linux 7.1 Rescue 95621d90ac5d4ae8a262fd52ed537a16 
(3.10.0-229.1.2.el7.x86_64) with debugging' --class fedora --class 
gnu-linux --class gnu --class os --unrestricted $menuentry_id_option 
'gnulinux-3.10.0-229.1.2.el7.x86_64-advanced-562d91f4-7086-451e-abc1-870f59bf3c41' 
{
	load_video
...


This happened on the top two, but on the bottom third one.
Correcting that those two boo-boos made it so the "rescue"
sections could boot.  But the main section (Nitrogen) give
a kernel panic:

      Failed to access perfctr msr (MSR c1 is 0)
      kernel panic -- not syncing:L VFS: Unable to mount root fs on 
unknown-block(0,0)

I documented it over on:
https://bugzilla.redhat.com/show_bug.cgi?id=1224434

-T

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