grub terms

[satimis]

Hi folks,

if root=/dev/hdd

whether root (hd3) ?

EXAMPLE:
Is follwoing entry correct?
/boot/grub/menu.lst

title LiveCD
        root (hd3) ???
        kernel /boot/lfscdkernel ro root=/dev/hdd vga=795

Pls advise. TIA

BR
satimis

[Demetrius]

First off, root cant be hdd. If '/' is the first partition on hdd then root=/dev/hdd1. That would make it hd3,0 for grub.

So assuming your kernel line is correct your Grub entry should look like:

title LiveCD
root (hd3,0)
kernel /boot/lfscdkernel ro root=/dev/hdd1 vga=795

[drakebasher]

Whether (Linux) hdd is same as (Grub) hd3 or (Grub) hd4 depends on how many hard drives are in your system. Linux and Grub "count" drives very differently:

• Linux
  Primary master = hda
  Primary slave = hdb
  Secondary master = hdc
  Secondary slave = hdd

This is correct for hard drives, CD drives and Zip drives, no matter how they are arranged and no matter how many there are.

• Grub
  "First" hard drive = hd0
  "Second" hard drive = hd1
  ...etc...

"First" and "Second" are in order of recognition: the boot device will always be "First" or (hd0). CD drives are not recognized by Grub, as far as I know, so they don't even count. The best way to see what is what, is to boot to the Grub prompt (grub>) and do:

grub> null &#40;hd  <tab>
grub> null &#40;hd0,  <tab>

When you press <tab>, Grub will show your choices kind of like Bash filename completion.

[satimis]

Hi Demetrius,

Tks for your advice. Sorry for not mentioning on my first posting. I'm building LFS LiveCD.

root=/dev/hdd is correct.

The LiveCD will be on CDRom which is connected as Slave secondary IDE. But I haven't figured out;

"root (hd3)" on the 2nd line. According to grub term;

    /dev/hda: 0
    /dev/hdb: 1
    /dev/hdc: 2
    /dev/hdd: 3 


/dev/hda1: 0,0
/dev/hda2: 0,1
/dev/hda3: 0,2
/dev/hda4: 0,3
/dev/hda5: 0,4
/dev/hda6: 0,5

I don't not whether I should put "root (hd3)" or "root (3)"

satimis

[satimis]

Hi drakebasher,

Tks for your advice.

I'm building a LFS LiveCD which will be inserted on CDRom connected as Slave on secondary IDE (dev/hdd). During booting it will boot from /dev/hdd.

I'm not quite sure whether /boot/grub/menu.lst will come into play at booting OR only the isolinux. If the former will come into play then what shall I put on the second line on menu.lst

title LiveCD
root (???)
kernel /boot/lfscdkernel ro root=/dev/hdd vga=795

The best way to see what is what, is to boot to the Grub prompt (grub>) and do:

grub> null &#40;hd  <tab>
grub> null &#40;hd0,  <tab>

When you press <tab>, Grub will show your choices kind of like Bash filename completion.

Whether you meant;

# cd /boot/grub/
[root@localhost grub]# null (hd1 <tab> -pressing "tab" with a space in between

device.map         grub.conf          minix_stage1_5     stage2
e2fs_stage1_5      iso9660_stage1_5   reiserfs_stage1_5  ufs2_stage1_5
fat_stage1_5       jfs_stage1_5       splash.xpm.gz      vstafs_stage1_5
ffs_stage1_5       menu.lst           stage1             xfs_stage1_5

[root@localhost grub]# null (hd1<tab>
If no space no printout.

Pls advise. TIA

BR
satimis

[drakebasher]

Whether you meant;

# cd /boot/grub/
[root@localhost grub]# null (hd1 <tab> -pressing "tab" with a space in between

device.map         grub.conf          minix_stage1_5     stage2
e2fs_stage1_5      iso9660_stage1_5   reiserfs_stage1_5  ufs2_stage1_5
fat_stage1_5       jfs_stage1_5       splash.xpm.gz      vstafs_stage1_5
ffs_stage1_5       menu.lst           stage1             xfs_stage1_5

[root@localhost grub]# null (hd1<tab>
If no space no printout.

Pls advise.

I meant to boot with Grub to get the Grub prompt, which looks like this: grub>
That would mean that you are in a Grub "environment". You can do that when you boot, by pressing "c" for the Grub command prompt, or from within Linux, with the command 'grub' (you may need to be root?). Of course, that's no good for you, since the "environment" you are interested in is from your CD when it is ready to boot. I'm afraid I have no idea what the answer to your question is. Maybe you don't even need a "root" statement. The purpose of that statement is just to tell Grub the location of the "base" of your system. The following 2 statement sets are equivalent:

root (hd0,0)
kernel /vmlinuz
...is equal to...
kernel (hd0,0)/vmlinuz

In the case where the kernel is on the same partition to whose boot record Grub is installed, I think that perhaps the root statement may be omitted. A quick experiment should prove the question.