On 29/01/13 20:40, Trenton Ray wrote:
> GRUB has a strange methodology (well, strange to me given that I'm one of a
> handful of neo-luddites still using LILO) for determining disks. It's got
> root as hd2,0 which means (and I may be mistaken) the 2nd disk, first
> partition.. which makes sense in accordance with /dev/sdb but since GRUB
> sees 0 as a value and not a null, maybe change it to 1,0 ? I fear I'm just
> going to add to the confusing at this point and apologize for not being able
> to help offhand.

Most commonly you'll find that:

/dev/sda -> hd0
/dev/sdb -> hd1
/dev/sdc -> hd2

And then with partitions:

/dev/sdX1 -> hdX,0
/dev/sdX2 -> hdX,1
/dev/sdX3 -> hdX,2
...
and so forth ...


>     [root@box7 bobg]# cat /boot/grub/grub.conf
>     # grub.conf generated by anaconda
>     #
>     # Note that you do not have to rerun grub after making changes to
>     this file
>     # NOTICE:  You have a /boot partition.  This means that
>     #          all kernel and initrd paths are relative to /boot/, eg.
>     #          root (hd2,0)
>     #          kernel /vmlinuz-version ro root=/dev/sdc3
>     #          initrd /initrd-[generic-]version.img
>     #boot=/dev/sdb

This line ^^^ can set to /dev/sda if you want GRUB on your MBR of
/dev/sda.  But remove the leading #

>     default=0
>     timeout=15
>     splashimage=(hd2,0)/grub/splash.xpm.gz

This looks for the splashimage (background graphics) from /dev/sdb1 ...
inside the grub/ directory on this partition.

If you mount /dev/sdb1 on /boot ... that means /boot/grub on your file
system.

>     hiddenmenu
>     title Scientific Linux (2.6.32-279.19.1.el6.x86_64)
>          root (hd2,0)

This expects kernels to be found on /dev/sdb1

>          kernel /vmlinuz-2.6.32-279.19.1.el6.x86_64 ro
>     root=UUID=088eabf7-7644-4acb-9017-bc510456357b rd_NO_LUKS rd_NO_LVM
>     LANG=en_US.UTF-8 rd_NO_MD SYSFONT=latarcyrheb-sun16
>     crashkernel=auto  KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb quiet
>          initrd /initramfs-2.6.32-279.19.1.el6.x86_64.img
>     title Scientific Linux (2.6.32-279.5.1.el6.x86_64)
>          root (hd2,0)

Same here as well.

>          kernel /vmlinuz-2.6.32-279.5.1.el6.x86_64 ro
>     root=UUID=088eabf7-7644-4acb-9017-bc510456357b rd_NO_LUKS rd_NO_LVM
>     LANG=en_US.UTF-8 rd_NO_MD SYSFONT=latarcyrheb-sun16
>     crashkernel=auto  KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb quiet
>          initrd /initramfs-2.6.32-279.5.1.el6.x86_64.img
>     title Other
>          rootnoverify (hd0,0)
>          chainloader +1

This would typically load Windows or so, installed on /dev/sda1

Hope this helps you understand the drive references a bit better.


--
kind regards,

David Sommerseth