Grub 2 Basics

[Cavsfan]

In Mint here is what blkid says:

/dev/sda1: UUID="1CFC7A8DFC7A60C6" TYPE="ntfs" 
/dev/sda2: UUID="deb59f40-8300-4f51-95b2-ab5492a4f2c6" TYPE="swap" 
/dev/sda3: UUID="a162dc8a-e4df-4b79-b4c3-524761ff7ae1" TYPE="ext4" 
/dev/sda5: UUID="283ef203-29c7-437f-9992-8ff6dad9f7e1" TYPE="ext4" 
/dev/sda6: UUID="4a88d030-5de4-4c4d-b5f3-9fb376f8df17" TYPE="swap" 
/dev/sda7: UUID="f2943974-0a9f-47ec-b5d4-7389c9be2ac0" TYPE="ext4" 
/dev/sda8: UUID="38870dc0-cd26-47a4-84b1-22c8467fa753" TYPE="ext4" 
/dev/sdb1: LABEL="Fantom" UUID="78B8D1A1B8D15DE6" TYPE="ntfs"

I'm 100% certain that sda5 is /boot, sda6 is swap, sda7 is / and sda8 is /home.
I ended up installing it 3 times and wrote them down.

But, my main OS (Ubuntu) sees the other one.

It doesn't see the windows7 partition and sdb1 is my 1TB USB drive.

Are you saying that this might work: (in red)

menuentry "Linux Mint 13 MATE 64-bit" {
        set root=(hd0,5)
        linux /vmlinuz root=/dev/sda7 ro quiet splash
        initrd /initrd.img
}

sda5 is /boot and sda7 is /.

Those are the correct addresses for what you describe so I would expect that menuentry to work.

I tried changing them to the above 5 and 7 in red and it still said you must load kernel first, press any key.

On thing I've found helpful is to label everything, such as "Mintboot", "Precise", "Mint", etc. It helps, especially with the blkid output, which includes labels.

sudo tune2fs -L "Mintboot" /dev/sda5

Thanks I did that and saved it.

I didn't really understand this part:

But, my main OS (Ubuntu) sees the other one.

It doesn't see the windows7 partition and sdb1 is my 1TB USB drive.

What I meant was I don't think either grub sees the same stuff. The one on Ubuntu sees it one way and the one on Mint sees it another.
The sda3 and sda8 are switched around. I don't know if that matters or not.
I was wrong by saying it doesn't see windows that is sda1.

I am on (GNU GRUB 1.98-1ubuntu13) here on Ubuntu. I check which version it is on Mint.

[Cavsfan]

Mint says

grub-install -v
unshare failed: Operation not permitted
grub-install.real (GRUB) 1.99-21ubuntu3

Not sure what that means before the version.

[drs305]

I think what is happening regarding sda3 and sda8 is that each is the 'home' folder for its own installation. If that is the case, what you are seeing is normal.

If you are running the OS that uses sda3 as /home, it would see sda8 as just another Linux partition and sda3 as its home folder.

If you are running the other OS, with sda8 as /home, vice versa.

It doesn't really matter to Grub, which doesn't consider /home in the boot process. It cares about root /, and /boot (or where the boot & grub files are). Other than that, it lets the system figure out where things are. That is one of the reasons some boots fail if the fstab is incorrect - Grub passes control to the kernel but then the system can't figure things out because one of the critical folders is incorrectly listed (or not) in fstab.

[Cavsfan]

I think what is happening regarding sda3 and sda8 is that each is the 'home' folder for its own installation. If that is the case, what you are seeing is normal.

If you are running the OS that uses sda3 as /home, it would see sda8 as just another Linux partition and sda3 as its home folder.

If you are running the other OS, with sda8 as /home, vice versa.

It doesn't really matter to Grub, which doesn't consider /home in the boot process. It cares about root /, and /boot (or where the boot & grub files are). Other than that, it lets the system figure out where things are. That is one of the reasons some boots fail if the fstab is incorrect - Grub passes control to the kernel but then the system can't figure things out because one of the critical folders is incorrectly listed (or not) in fstab.

I guess the only thing I know to do is hard code the last mint kernel and recovery in my 06_custom file.
It won't be perfectly maintenance free but, pretty close. Just a minor change if a kernel comes down the pipe.
I am not sure how long I will deal with LMDE 13 Mate anyway.
If you come up with anything else let me know.
Thanks for your time!

[luofeiyu]

i make a rescue grub usb this way .
sudo grub-mkrescue --output=rescue.iso
sudo dd if=~/rescue.iso of=/dev/sdb

my grub.cfg is:

menuentry 'Debian GNU/Linux, with Linux 2.6.32-5-686' --class debian --class gnu-linux --class gnu --class os {
insmod part_msdos
insmod ext2
set root='(/dev/sda,msdos5)'
search --no-floppy --fs-uuid --set 069ca903-d3d9-43ef-8e1e-02a27109fce3
echo 'Loading Linux 2.6.32-5-686 ...'
linux /vmlinuz-2.6.32-5-686 root=UUID=a28fd0a3-5391-4ac5-8206-3c97e53dc605 ro quiet
echo 'Loading initial ramdisk ...'
initrd /initrd.img-2.6.32-5-686
}


menuentry "Microsoft Windows XP Professional" {
set root=(hd0,msdos1)
search --no-floppy --fs-uuid --set f888-ccdb
drivemap -s (hd0) $root
chainloader +1
}

now , i reinstall my xp,then i can't use my debian .
i reboot with my usb,when i get grub>
1.boot xp
input ls ,the hd0 turn into hd1,my usb is hd0,
so i input
grub>set root=(hd0,msdos1)
grub>search --no-floppy --fs-uuid --set f888-ccdb
grub>drivemap -s (hd0) $root
grub>chainloader +1
grub>boot

it's ok! i can boot xp.

2.boot debian
i input:
grub>insmod part_msdos
grub>insmod ext2
grub>set root='(hd1,msdos5)'
grub>linux /vmlinuz-2.6.32-5-686 root=UUID=a28fd0a3-5391-4ac5-8206-3c97e53dc605 ro quiet
grub>initrd /initrd.img-2.6.32-5-686
grub>boot

i can't boot debian,what's wrong in my grub command?

[drs305]

2.boot debian
i input:
grub>insmod part_msdos
grub>insmod ext2
grub>set root='(hd1,msdos5)'
grub>linux /vmlinuz-2.6.32-5-686 root=UUID=a28fd0a3-5391-4ac5-8206-3c97e53dc605 ro quiet
grub>initrd /initrd.img-2.6.32-5-686
grub>boot

i can't boot debian,what's wrong in my grub command?

I can only compare your menuentry with what we normally see. In Ubuntu the normal setup, unless you have a separate 'boot' partition, has a symlink (/vmlinuz) in / and the actual kernel in /boot (/boot/vmlinuz-3-0.....).

In your example, you are specifying the actual kernel and initrd image as residing in / rather than /boot. So in the above example it would normally be: grub>linux /vmlinuz ... or grub>linux /boot/vmlinuz-2.6...

If this isn't the problem I'd recommend installing and running the Boot Repair app from a LiveCD.

[luofeiyu]

i have separate '/boot' partition and '/' partition.

it's so strange for my system ,i can boot it with my rescue cd,but i can't boot it with my rescue usb,the same grub command
grub>insmod part_msdos
grub>insmod ext2
grub>set root='(hd1,msdos5)'
grub>linux /vmlinuz-2.6.32-5-686 \root=UUID=a28fd0a3-5391-4ac5-8206-3c97e53dc605 ro quiet
grub>initrd /initrd.img-2.6.32-5-686
grub>boot

to boot in from my rescue usb ,what i get is :
/bin/sh :can't access tty ;job control turned off

[luofeiyu]

grub>insmod part_msdos
grub>insmod ext2
grub>set root='(hd1,msdos5)'
grub>linux /vmlinuz-2.6.32-5-686 \root=UUID=a28fd0a3-5391-4ac5-8206-3c97e53dc605 rootdelay=60 ro quiet
grub>initrd /initrd.img-2.6.32-5-686
grub>boot

when i add rootdelay=60,it works fine.

[luofeiyu]

i still have a problem ,if i want to install ppp-udeb ,how to write my command?
linux /vmlinuz-2.6.32-5-686 append install modules=ppp.udeb
??

[drs305]

i still have a problem ,if i want to install ppp-udeb ,how to write my command?
linux /vmlinuz-2.6.32-5-686 append install modules=ppp.udeb
??

I'm not familiar enough with this to advise you. I recommend you start a thread of your own and you will probably get a quicker answer than having your question 'buried' in this thread.