Grub2 failings
Peter Zoeller
peter_zoeller at rogers.com
Sat Aug 4 18:47:33 UTC 2012
I had the pleasure of upgrading my system recently from F15 to F16. The
upgrade using PreUpgrade worked beautifully. However what trashed my
system was Grub2. In my estimation grub2 is a kludge and it doesn't
work properly. Grub was a beautiful step up from Lilo both in
simplicity, ease of use and ease of control. Grub2 in my estimation is
a regression. It obviously is written by a bunch of Microsoft heads who
totally miss the KISS principle. I have gone back to installing and
using grub.
So how did it break my system. It doesn't read the drive geometry
correctly. It is a step back by assigning hex code to partitions and
does so incorrectly. I thought I had seen the last of hex code when I
left college in the seventies and had to learn to read core dumps. Now
I find I have to relearn it in order to deal with UUID assignments. No
wonder Linux doesn't make it into the mainstream.
A boot loader is supposed to boot a system and that is all it should do
which grub does marvelously well. System setup and configuration should
and must be left to the operating systems and systemd. To display what
I mean by grub2 screwing things up let me show you.
Fdisk of my main drive...
[root at HawksNest grayhawk]# fdisk /dev/sda
Command (m for help): p
Disk /dev/sda: 160.0 GB, 160041885696 bytes
255 heads, 63 sectors/track, 19457 cylinders, total 312581808 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000b485f
Device Boot Start End Blocks Id System
/dev/sda1 * 63 144584999 72292468+ 83 Linux
/dev/sda2 144585000 186530714 20972857+ 83 Linux
/dev/sda3 186530715 225616859 19543072+ 83 Linux
/dev/sda4 225616860 312576704 43479922+ 5 Extended
/dev/sda5 225616923 264703004 19543041 83 Linux
/dev/sda6 264703068 303789149 19543041 83 Linux
/dev/sda7 303789213 312576704 4393746 82 Linux swap /
Solaris
Df of my partitions as read when they are mounted.....
[root at HawksNest ~]# df -T
Filesystem Type 1K-blocks Used Available Use% Mounted on
rootfs rootfs 71104256 32761604 34728032 49% /
devtmpfs devtmpfs 991944 0 991944 0% /dev
tmpfs tmpfs 1000572 264 1000308 1% /dev/shm
tmpfs tmpfs 1000572 692 999880 1% /run
/dev/sda1 ext3 71104256 32761604 34728032 49% /
tmpfs tmpfs 1000572 0 1000572 0% /sys/fs/cgroup
tmpfs tmpfs 1000572 0 1000572 0% /media
/dev/sda2 ext3 20596820 12864132 6684048 66% /mnt/sda2
/dev/sda3 reiserfs 19542436 14015280 5527156 72% /mnt/sda3
/dev/sda5 reiserfs 19542436 12561496 6980940 65% /mnt/sda5
/dev/sda6 ext3 19191340 4730784 13483404 26% /mnt/sda6
Here is the grub2 configuration file that messed up the system
### BEGIN /etc/grub.d/10_linux ###
menuentry 'Fedora (3.4.6-1.fc16.i686.PAE)' --class fedora --class
gnu-linux --class gnu --class os {
load_video
set gfxpayload=keep
insmod gzio
insmod part_msdos
insmod ext2
set root='(hd0,msdos1)'
search --no-floppy --fs-uuid --set=root
abc67dd1-53b1-47ca-a27f-0c7d84829f51
echo 'Loading Fedora (3.4.6-1.fc16.i686.PAE)'
linux /boot/vmlinuz-3.4.6-1.fc16.i686.PAE
root=UUID=6c3c0e3d-2708-439f-beb7-b9937d1d5f0a ro rd.md=0 rd.lvm=0
rd.dm=0 KEYTABLE=us quiet SYSFONT=latarcyrheb-sun16 rhgb rd.luks=0
LANG=en_US.UTF-8
echo 'Loading initial ramdisk ...'
initrd /boot/initramfs-3.4.6-1.fc16.i686.PAE.img
}
menuentry 'Fedora Linux, with Linux 3.4.4-4.fc16.i686.PAE' --class
fedora --class gnu-linux --class gnu --class os {
load_video
set gfxpayload=keep
insmod gzio
insmod part_msdos
insmod ext2
set root='(hd0,msdos1)'
search --no-floppy --fs-uuid --set=root
abc67dd1-53b1-47ca-a27f-0c7d84829f51
echo 'Loading Linux 3.4.4-4.fc16.i686.PAE ...'
linux /boot/vmlinuz-3.4.4-4.fc16.i686.PAE
root=UUID=abc67dd1-53b1-47ca-a27f-0c7d84829f51 ro rd.md=0 rd.lvm=0
rd.dm=0 KEYTABLE=us quiet SYSFONT=latarcyrheb-sun16 rhgb rd.luks=0
LANG=en_US.UTF-8
echo 'Loading initial ramdisk ...'
initrd /boot/initramfs-3.4.4-4.fc16.i686.PAE.img
}
menuentry 'Fedora Linux, with Linux 3.4.4-4.fc16.i686.PAE (recovery
mode)' --class fedora --class gnu-linux --class gnu --class os {
load_video
set gfxpayload=keep
insmod gzio
insmod part_msdos
insmod ext2
set root='(hd0,msdos1)'
search --no-floppy --fs-uuid --set=root
abc67dd1-53b1-47ca-a27f-0c7d84829f51
echo 'Loading Linux 3.4.4-4.fc16.i686.PAE ...'
linux /boot/vmlinuz-3.4.4-4.fc16.i686.PAE
root=UUID=abc67dd1-53b1-47ca-a27f-0c7d84829f51 ro single rd.md=0
rd.lvm=0 rd.dm=0 KEYTABLE=us quiet SYSFONT=latarcyrheb-sun16 rhgb
rd.luks=0 LANG=en_US.UTF-8
echo 'Loading initial ramdisk ...'
initrd /boot/initramfs-3.4.4-4.fc16.i686.PAE.img
}
### END /etc/grub.d/10_linux ###
### BEGIN /etc/grub.d/20_linux_xen ###
### END /etc/grub.d/20_linux_xen ###
### BEGIN /etc/grub.d/30_os-prober ###
menuentry "Fedora (2.6.38.6-26.rc1.fc15.i686.PAE) (on /dev/sda2)"
--class gnu-linux --class gnu --class os {
insmod part_msdos
insmod ext2
set root='(hd0,msdos2)'
search --no-floppy --fs-uuid --set=root
6c3c0e3d-2708-439f-beb7-b9937d1d5f0a
linux /boot/vmlinuz-2.6.38.6-26.rc1.fc15.i686.PAE ro root=/dev/sda1
KEYTABLE=us rhgb quiet
initrd /boot/initramfs-2.6.38.6-26.rc1.fc15.i686.PAE.img
}
menuentry "Fedora (2.6.38.6-26.rc1.fc15.i686.PAE) (on /dev/sda2)"
--class gnu-linux --class gnu --class os {
insmod part_msdos
insmod ext2
set root='(hd0,msdos2)'
search --no-floppy --fs-uuid --set=root
6c3c0e3d-2708-439f-beb7-b9937d1d5f0a
linux /boot/vmlinuz-2.6.38.6-26.rc1.fc15.i686.PAE ro root=/dev/sda2
KEYTABLE=us rhgb quiet
initrd /boot/initramfs-2.6.38.6-26.rc1.fc15.i686.PAE.img
}
menuentry "KNOPPIX (on /dev/sda3)" --class gnu-linux --class gnu --class
os {
insmod part_msdos
insmod reiserfs
set root='(hd0,msdos3)'
search --no-floppy --fs-uuid --set=root
8cd61602-4981-4b11-a2f8-8e06bd4baff2
linux /boot/vmlinuz root=/dev/sda1 rootwait lang=us apm=power-off
nomce libata.force=noncq tz=localtime loglevel=1 rw
}
menuentry "Debian GNU/Linux, kernel 2.6.37-64 Default (on /dev/sda3)"
--class gnu-linux --class gnu --class os {
insmod part_msdos
insmod reiserfs
set root='(hd0,msdos3)'
search --no-floppy --fs-uuid --set=root
8cd61602-4981-4b11-a2f8-8e06bd4baff2
linux /boot/vmlinuz-2.6.37-64 root=/dev/sda1 ro lang=us
apm=power-off tz=localtime vga=791
}
menuentry "KNOPPIX (on /dev/sda5)" --class gnu-linux --class gnu --class
os {
insmod part_msdos
insmod reiserfs
set root='(hd0,msdos5)'
search --no-floppy --fs-uuid --set=root
89b7ce78-6ccf-4fc4-9af2-2a392494473b
linux /boot/vmlinuz root=/dev/sda5 rootwait lang=us apm=power-off
vga=791 nomce loglevel=0 quiet rw
}
menuentry "Fedora (2.6.38.6-26.rc1.fc15.i686.PAE) (on /dev/sda6)"
--class gnu-linux --class gnu --class os {
insmod part_msdos
insmod ext2
set root='(hd0,msdos6)'
search --no-floppy --fs-uuid --set=root
44c1d6b1-51f2-4eac-880f-9262996556d6
linux /boot/vmlinuz-2.6.38.6-26.rc1.fc15.i686.PAE ro
root=UUID=44c1d6b1-51f2-4eac-880f-9262996556d6 rd_NO_LUKS rd_NO_LVM
rd_NO_MD rd_NO_DM LANG=en_US.UTF-8 SYSFONT=latarcyrheb-sun16 KEYTABLE=us
rhgb quiet
initrd /boot/initramfs-2.6.38.6-26.rc1.fc15.i686.PAE.img
}
So what are the issues with this....
I have two fedora partitions sda1 and sda2. It no longer boots the
second installation which is a different version of Fedora. I teach
Linux and use other installations to learn differences between distros
in order to bring this knowledge to class. The second Fedora is not my
live system but the same as what was being used in the class.
The third partition sda3 is a reiser file system and a Knoppix hard
drive install installed and modified as a Debian distribution. Under
grub2 it no longer boots because the kernel can't find the file system.
Why grub2 is telling it to look in the wrong place.
The fifth partition sda5 is a pure Knoppix hard drive install and funny
enough it does boot.
The remaining one sda6 is at the moment a bad install and should not be
part of the boot menu. It is used to install and test out and learn
other distros. With grub it was child's play to install other distros
make a mod to the grub.conf to include or exclude the new distro. You
no longer had to rerun like you did with Lilo and now with grub2 your
are back to Lilo times where you must rerun grub2 to have the new
configuration installed. Talk about taking a step back.
With Lilo and grub it was easy from the boot loader screen to directly
boot into a kernel shell to rescue a pooched hard drive. Like to see how
you can do that using grub2?
I have reverted back to using grub, a system that is elegant, simple,
well designed and dumped the kludge that grub2 is. I shall continue to
use grub and our file server at work that I maintain shall also continue
to use grub. I will warn my students about the failures of grub2 and
let them decide whether to upgrade to grub2 or stick with grub.
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