Grub 2 Basics

[moore.bryan]

Is there seriously no way of completely hiding the grub menu on a dual-boot pc?

[drs305]

Is there seriously no way of completely hiding the grub menu on a dual-boot pc?

In talking to some of the devs it appears like it may be an Ubuntu/GRUB interface bug rather than an bug in GRUB itself.

EDITED: While I don't know what is being done to fix it, a semi-workaround might be to set both timeouts to "0" so the system boots without displaying the menu. What you lose is the ability to change what you can boot to via the bootloader until you change the menu, since the option of holding down the SHIFT key would not work. With the default timeout of zero it would immediately boot the system without showing the menu.

I keep trying different settings and looking at the files involved in the process. Hopefully someone will eventually figure this one out.

[moore.bryan]

Thanks for the tip drs305, but setting the timeout to zero only boots the default os immediately and holding-down the Shift key does nothing.
!

[frafu]

Hi,


By setting GRUB_DEFAULT=saved in /etc/default/grub, update-grub adds saved_entry=${chosen} to every menu entry in /boot/grub/grub.cfg.

However I need it to add saved_entry=0 to every menu entry in /boot/grub/grub.cfg.

Can anybody please tell me how it should be done? For the moment I am doing it by editing the grub.cfg file.


Or is there a way I can choose the entry to use to boot with the pointer? (That would be an alternative, even better solution to my problem.)


Thanks in advance for any reply.

Francesco

[frafu]

Hi,

Replying to myself for the case somebody has a similar problem. Here is what I did:

- I disabled 20_memtest86+ and 30_os-prober by doing a "sudo chmod 644" on these files. This way, the menu entries for the other operating systems are not created in grub.cfg

- I manually created the menu entries for the other operating systems in 40_custom and added the following two lines to each entry to reset the value to 0:
saved_entry=0
save_env saved_entry


However, if there is a way to choose the menu entry with the pointer when grub2 shows the menu, that would be better.


Cheers,

Francesco

[ranch hand]

Well, I am trying to get my two internal HDDs reorganized for 10.04 testing and I need to be able to boot from sda for both and sdb for just sdb.

This worked great for me if sdb was external.

I have PhatDebian on sda and installed grub2 on it. Works great on sda (4 OS').

I have 9.10 on sdb and it works great on sdb when I turn off sda.

When I try to boot to either of the OS' currently on sdb from sda I get the song and dance about needing to mount the kernel first.

I tried installing to the MBR of sdb instead of sda and this continued to work for sda but not for sdb. It did, of coarse, screw booting on sdb when it was the only drive on. I just fixed that.

So, how do you get grub2 to boot 2 internal HDDs? I have nothing on here, now but Debian based OS'.

jak@jak-desktop:~$ blkid
/dev/sda1: UUID="3f89f003-c61d-4de5-9da8-9665cfe0b442" SEC_TYPE="ext2" TYPE="ext3" LABEL="Ph.D-B2-root"
/dev/sda3: LABEL="Jaunty-64" UUID="4ac13ed4-c6af-4965-ad49-5dc81641814f" TYPE="ext4"
/dev/sda5: TYPE="swap"
/dev/sda6: LABEL="Stoner-64-root" UUID="f8e427dd-f406-495b-a1ac-a9354c841a45" TYPE="ext4"
/dev/sda7: LABEL="Stoner-64-home" UUID="6c29ec93-c9e5-44ec-9e55-cfb1dccda6bc" TYPE="ext4"
/dev/sda8: UUID="a7ed8e99-2c87-497d-af02-39948658eb4f" SEC_TYPE="ext2" TYPE="ext3" LABEL="Debian-root"
/dev/sda9: LABEL="Debian-home" UUID="df117f65-b942-49d2-9811-5d7e0b6d937d" SEC_TYPE="ext2" TYPE="ext3"
/dev/ramzswap0: TYPE="swap"
/dev/sda4: UUID="d2665c89-ef8a-40ff-87e9-672b5a7c1efc" SEC_TYPE="ext2" TYPE="ext3" LABEL="Ph.D-B2-home"
/dev/sdb5: TYPE="swap"
/dev/sdb6: UUID="a4a911c2-0abb-4c5f-87ac-147bf796b6c7" SEC_TYPE="ext2" TYPE="ext3" LABEL="Ph.D-home"
/dev/sdb7: UUID="b211ec8b-329a-42d4-8ca4-00d1d87ac8c6" SEC_TYPE="ext2" TYPE="ext3" LABEL="Ph.D-root"
/dev/sdb8: UUID="99de3e95-b76e-4f0b-bb2f-be7f8b3250a2" TYPE="ext4" LABEL="Kinky-home"
/dev/sdb9: UUID="da21d101-5934-40af-8eb7-3de18c187a95" TYPE="ext4" LABEL="Kinky-root"
/dev/sdb10: UUID="7894403b-bc9f-445d-87ba-d091a55134f7" TYPE="ext4"
/dev/sdb11: UUID="e765a4fa-0d7b-4972-96cf-db358c07a1db" TYPE="ext4"

There is nothing on sdb10 or sdb11 currently.

All uuids match up fine with the menu.

### BEGIN /etc/grub.d/06_custom ###
# This file is an example on how to add custom entries

echo "Adding Stoner-64 on sda6" >&2
cat << EOF
menuentry "Stoner-64 on sda6" {
set root=(hd0,6)
linux /vmlinuz root=/dev/sda6 so quiet splash
initrd /initrd.img
}
EOF

echo "Adding PhatDebian on sda1" >&2
cat << EOF
menuentry "PhatDebian on sda1" {
set root=(hd0,1)
linux /vmlinuz root=/dev/sda1 so quiet splash
initrd /initrd.img
}
EOF

echo "Adding Jaunty-64 on sda3" >&2
cat << EOF
menuentry "Jaunty-64 on sda3" {
set root=(hd0,3)
linux /vmlinuz root=/dev/sda3 so quiet splash
initrd /initrd.img
}
EOF

echo "Adding Debian on sda8" >&2
cat << EOF
menuentry "Debian on sda8" {
set root=(hd0,8)
linux /vmlinuz root=/dev/sda8 so quiet splash
initrd /initrd.img
}
EOF

echo "Adding PhatDebian-64 on sdb7" >&2
cat << EOF
menuentry "PhatDebian-64 on sdb7" {
set root=(hd1,7)
linux /vmlinuz root=/dev/sdb7 so quiet splash
initrd /initrd.img
}
EOF

echo "Adding KinkyFR on sdb9" >&2
cat << EOF
menuentry "KinkyFR on sdb9" {
set root=(hd1,9)
linux /vmlinuz root=/dev/sdb9 so quiet splash
initrd /initrd.img
}
EOF




### END /etc/grub.d/06_custom ###

### BEGIN /etc/grub.d/10_hurd ###
### END /etc/grub.d/10_hurd ###

### BEGIN /etc/grub.d/10_linux ###
menuentry "Debian GNU/Linux, linux 2.6.30-bpo.1-amd64" {
set root=(hd0,1)
search --fs-uuid --set 3f89f003-c61d-4de5-9da8-9665cfe0b442
linux /boot/vmlinuz-2.6.30-bpo.1-amd64 root=UUID=3f89f003-c61d-4de5-9da8-9665cfe0b442 ro y
initrd /boot/initrd.img-2.6.30-bpo.1-amd64
}
menuentry "Debian GNU/Linux, linux 2.6.30-bpo.1-amd64 (single-user mode)" {
set root=(hd0,1)
search --fs-uuid --set 3f89f003-c61d-4de5-9da8-9665cfe0b442
linux /boot/vmlinuz-2.6.30-bpo.1-amd64 root=UUID=3f89f003-c61d-4de5-9da8-9665cfe0b442 ro single y
initrd /boot/initrd.img-2.6.30-bpo.1-amd64
}
menuentry "Debian GNU/Linux, linux 2.6.26-2-amd64" {
set root=(hd0,1)
search --fs-uuid --set 3f89f003-c61d-4de5-9da8-9665cfe0b442
linux /boot/vmlinuz-2.6.26-2-amd64 root=UUID=3f89f003-c61d-4de5-9da8-9665cfe0b442 ro y
initrd /boot/initrd.img-2.6.26-2-amd64
}
menuentry "Debian GNU/Linux, linux 2.6.26-2-amd64 (single-user mode)" {
set root=(hd0,1)
search --fs-uuid --set 3f89f003-c61d-4de5-9da8-9665cfe0b442
linux /boot/vmlinuz-2.6.26-2-amd64 root=UUID=3f89f003-c61d-4de5-9da8-9665cfe0b442 ro single y
initrd /boot/initrd.img-2.6.26-2-amd64
}
### END /etc/grub.d/10_linux ###

### BEGIN /etc/grub.d/20_memtest86+ ###
menuentry "Memory test (memtest86+)" {
linux /memtest86+.bin
}
### END /etc/grub.d/20_memtest86+ ###

### BEGIN /etc/grub.d/30_os-prober ###
menuentry "Ubuntu 9.04, kernel 2.6.28-16-generic (on /dev/sda3)" {
set root=(hd0,3)
linux /boot/vmlinuz-2.6.28-16-generic root=UUID=4ac13ed4-c6af-4965-ad49-5dc81641814f ro quiet splash
initrd /boot/initrd.img-2.6.28-16-generic
}
menuentry "Ubuntu 9.04, kernel 2.6.28-16-generic (recovery mode) (on /dev/sda3)" {
set root=(hd0,3)
linux /boot/vmlinuz-2.6.28-16-generic root=UUID=4ac13ed4-c6af-4965-ad49-5dc81641814f ro single
initrd /boot/initrd.img-2.6.28-16-generic
}
menuentry "Ubuntu 9.04, kernel 2.6.28-15-generic (on /dev/sda3)" {
set root=(hd0,3)
linux /boot/vmlinuz-2.6.28-15-generic root=UUID=4ac13ed4-c6af-4965-ad49-5dc81641814f ro quiet splash
initrd /boot/initrd.img-2.6.28-15-generic
}
menuentry "Ubuntu 9.04, kernel 2.6.28-15-generic (recovery mode) (on /dev/sda3)" {
set root=(hd0,3)
linux /boot/vmlinuz-2.6.28-15-generic root=UUID=4ac13ed4-c6af-4965-ad49-5dc81641814f ro single
initrd /boot/initrd.img-2.6.28-15-generic
}
menuentry "Ubuntu 9.04, memtest86+ (on /dev/sda3)" {
set root=(hd0,3)
linux /boot/memtest86+.bin
}
menuentry "Debian GNU/Linux, kernel memtest86+ (on /dev/sda3)" {
set root=(hd0,3)
linux /boot/memtest86+.bin
}
menuentry "Stoner Edition, 2.6.28-16-generic (on /dev/sda6)" {
set root=(hd0,6)
linux /boot/vmlinuz-2.6.28-16-generic root=UUID=f8e427dd-f406-495b-a1ac-a9354c841a45 ro quiet splash
initrd /boot/initrd.img-2.6.28-16-generic
}
menuentry "Stoner Edition, 2.6.28-16-generic (recovery mode) (on /dev/sda6)" {
set root=(hd0,6)
linux /boot/vmlinuz-2.6.28-16-generic root=UUID=f8e427dd-f406-495b-a1ac-a9354c841a45 ro single
initrd /boot/initrd.img-2.6.28-16-generic
}
menuentry "Ubuntu 9.04, memtest86+ (on /dev/sda6)" {
set root=(hd0,6)
linux /boot/memtest86+.bin
}
menuentry "Jaunty, kernel 2.6.28-16-generic (on /dev/sda6)" {
set root=(hd0,6)
linux /boot/vmlinuz-2.6.28-16-generic root=UUID=4ac13ed4-c6af-4965-ad49-5dc81641814f ro quiet splash
initrd /boot/initrd.img-2.6.28-16-generic
}
menuentry "Jaunty, kernel 2.6.28-16-generic (recovery mode) (on /dev/sda6)" {
set root=(hd0,6)
linux /boot/vmlinuz-2.6.28-16-generic root=UUID=4ac13ed4-c6af-4965-ad49-5dc81641814f ro single
initrd /boot/initrd.img-2.6.28-16-generic
}
menuentry "Debian GNU/Linux, kernel 2.6.26-2-amd64 (on /dev/sda8)" {
set root=(hd0,8)
linux /boot/vmlinuz-2.6.26-2-amd64 root=/dev/sda8 ro quiet
initrd /boot/initrd.img-2.6.26-2-amd64
}
menuentry "Debian GNU/Linux, kernel 2.6.26-2-amd64 (single-user mode) (on /dev/sda8)" {
set root=(hd0,8)
linux /boot/vmlinuz-2.6.26-2-amd64 root=/dev/sda8 ro single
initrd /boot/initrd.img-2.6.26-2-amd64
}
menuentry "Debian GNU/Linux, kernel 2.6.30-bpo.1-amd64 (on /dev/sdb7)" {
set root=(hd1,7)
linux /boot/vmlinuz-2.6.30-bpo.1-amd64 root=UUID=b211ec8b-329a-42d4-8ca4-00d1d87ac8c6 ro
initrd /boot/initrd.img-2.6.30-bpo.1-amd64
}
menuentry "Debian GNU/Linux, kernel 2.6.30-bpo.1-amd64 (single-user mode) (on /dev/sdb7)" {
set root=(hd1,7)
linux /boot/vmlinuz-2.6.30-bpo.1-amd64 root=UUID=b211ec8b-329a-42d4-8ca4-00d1d87ac8c6 ro single
initrd /boot/initrd.img-2.6.30-bpo.1-amd64
}
menuentry "Debian GNU/Linux, kernel 2.6.26-2-amd64 (on /dev/sdb7)" {
set root=(hd1,7)
linux /boot/vmlinuz-2.6.26-2-amd64 root=UUID=b211ec8b-329a-42d4-8ca4-00d1d87ac8c6 ro
initrd /boot/initrd.img-2.6.26-2-amd64
}
menuentry "Debian GNU/Linux, kernel 2.6.26-2-amd64 (single-user mode) (on /dev/sdb7)" {
set root=(hd1,7)
linux /boot/vmlinuz-2.6.26-2-amd64 root=UUID=b211ec8b-329a-42d4-8ca4-00d1d87ac8c6 ro single
initrd /boot/initrd.img-2.6.26-2-amd64
}
menuentry "Debian GNU/Linux, kernel memtest86+ (on /dev/sdb7)" {
set root=(hd1,7)
linux /boot/memtest86+.bin
}
menuentry "KinkyFR on sda9 (on /dev/sdb9)" {
set root=(hd1,9)
linux /vmlinuz root=/dev/sda9 so quiet splash
initrd /initrd.img
}
menuentry "PhatDebian on sda7 (on /dev/sdb9)" {
set root=(hd1,9)
linux /vmlinuz root=/dev/sda7 so quiet splash
initrd /initrd.img
}
menuentry "PhatDebian on sda7 (on /dev/sdb9)" {
set root=(hd1,9)
linux /vmlinuz root=/dev/sda7 so quiet splash
initrd /initrd.img
}
menuentry "Ubuntu, Linux 2.6.31-14-generic (on /dev/sdb9)" {
set root=(hd1,9)
linux /boot/vmlinuz-2.6.31-14-generic root=UUID=da21d101-5934-40af-8eb7-3de18c187a95 ro quiet splash
initrd /boot/initrd.img-2.6.31-14-generic
}
menuentry "Ubuntu, Linux 2.6.31-14-generic (recovery mode) (on /dev/sdb9)" {
set root=(hd1,9)
linux /boot/vmlinuz-2.6.31-14-generic root=UUID=da21d101-5934-40af-8eb7-3de18c187a95 ro single
initrd /boot/initrd.img-2.6.31-14-generic
}
### END /etc/grub.d/30_os-prober ###

### BEGIN /etc/grub.d/40_custom ###
# This file is an example on how to add custom entries
### END /etc/grub.d/40_custom ###

I get the same error with my custom entries as with the generated entries.

[ranch hand]

Just an update.

I was trying to boot with PhatDebian as the root. The only problem that I could see was that the grub2 version was 1.96.

Having a Jaunty install on that same drive, I popped over there and it had the same thing in the repos. Enabled a karmic repo and checked again and there it was, 1.97beta4. Installed that and tried it.

Different grub2, same result. Bummer.

[ranch hand]

Another update;

I thought maybe turning off sdb and updating grub so that only sda was on the bugger would help. I made sure the the fstab an device map reflected only sda.

Then I turned sdb back on, chrooted into the 9.10 there and updated grub so that it was on sdb instead of sda (I have been using it as the only drive turned on).

Then updated grub on sda again. Same old song and dance still.

Now I need to boot the LiveCD and rescue grub on 9.10 on sdb again.

What FUN. And people wonder why I don't play games on here.

[tz1]

Chainloading DOS - on the first partition.

This took me an hour to figure out (mostly random scattershot until something worked).

1. (hd0) and (hd1) might be reversed from the BIOS v.s. linux, so although it ends up being sdb1 when linux boots, I have to specify (hd0,1).

2. You can use "chainloader (hd0,1)+1" without anything else which is what I needed, but also files or other devices.

Something as simple as this isn't documented anywhere.

http://members.iinet.net/%7Eherman546/p20.html has the best documentation on Grub2.

[MountainX]

1. 
   
   • Mount devices:

     sudo mount --bind /dev/ /mnt/dev

   • Chroot into your normal system device:

     sudo chroot /mnt

   • Reinstall GRUB 2:

     sudo grub-install /dev/sdX

   • 
     
     • Note: Substitute the correct device - sda, sdb, etc. Do ''not'' specify a partition number.
     
     

Hi. Thanks for the excellent guide. Can anyone explain what the result of the above steps are? In particular, I want to install grub to a partition and I do not want to touch the disk's MBR.

I have a separate boot partition where grub resides independently from any OS. I use chainloading to boot a number of OS's. Each OS has its own bootloader in its partition. All is working except for Mythbuntu.

I just sbooted up with Mythbuntu 9.10 LiveCD and now I want to fix Mythbuntu not booting.

Mythbuntu is installed on /dev/sda9. My separate boot partition (which is working) is on /dev/sda1 and it is presently not mounted (in order to avoid creating any new issues).

I have done all the steps up to chroot. Now I am ready to run:

sudo grub-install /dev/sda

but I wish I could do this to be sure of where things were going:

sudo grub-install /dev/sda9

I do not want this to touch the sda MBR. (As per above, all other OS's are booting perfectly via chainloading.) I only want to get Mythbuntu to boot now (which I believe requires putting grub into sda9).