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Re: Possibly erroneous "device not present" message during boot




On 04/12/2017 02:23 PM, Brian wrote:
On Wed 12 Apr 2017 at 13:33:02 -0500, Richard Owlett wrote:

On theory "too much better than too little" I see:
<begin quote>
### BEGIN /etc/grub.d/20_linux_xen ###

### END /etc/grub.d/20_linux_xen ###

### BEGIN /etc/grub.d/30_os-prober ###
menuentry 'Debian GNU/Linux (8.6) (on /dev/mmcblk0p1)' --class gnu-linux
--class gnu --class os $menuentry_id_option
'osprober-gnulinux-simple-380e2a6d-f851-4fd1-9db2-869a0982b511' {
	insmod part_msdos
	insmod ext2
	if [ x$feature_platform_search_hint = xy ]; then
	  search --no-floppy --fs-uuid --set=root
380e2a6d-f851-4fd1-9db2-869a0982b511
	else
	  search --no-floppy --fs-uuid --set=root
380e2a6d-f851-4fd1-9db2-869a0982b511
	fi
	linux /boot/vmlinuz-3.16.0-4-686-pae root=/dev/mmcblk0p1
	initrd /boot/initrd.img-3.16.0-4-686-pae
}
<end quote>

GRUB is content to boot whatever is on the SD (as you observe) so must
be happy enough with the stanza above; there is no problem with booting
there. Actually, GRUB only uses

 linux /boot/vmlinuz-3.16.0-4-686-pae root=/dev/mmcblk0p1

and

 initrd /boot/initrd.img-3.16.0-4-686-pae

to get everything up and running. Without those two lines you would not
be booting.

So try this:
When the GRUB menu displays press the "e" key and remove the

  search --no-floppy --fs-uuid --set=root 380e2a6d-f851-4fd1-9db2-869a0982b511

Then press the "F10" key. Can you still boot? Do you get the onscreen
message you are concerned about?



Something *ODD* is going on in that area.
As that string appears in both the "then" and "else" clauses I:
  1. tried removing them individually leaving a blank line.
     For both cases grub crashed with a syntax error.
  2. removed entire if-then-else-fi construct.
     That booted without the "device not found" message.
  3. changed the last digit of the UUID.
     That demonstrated that the "then" clause was the one executed.
  4. used gparted to change the UUID of the SD card.
     That crashed in ways seemingly unrelated to anything.
     I'm going to update my preferred preseed.cfg and reinstall to
     both /dev/sda1 and the SD card in a reproducible way.

What log files should I save after each test boot.