Grub Manual ... Solved

[William Case]

Hi Gene;

I was very glad to see your post.  Comments below ...

On Sat, 2007-10-20 at 12:33 -0400, Gene Heskett wrote:
> On Saturday 20 October 2007, Karl Larsen wrote:

> 
> And I have, if you'll check the archives back when RH7-8-9 was new, instructed 
> many people on the finer points of grubs use, or miss-use, of the 'root' 
> keyword.  I personally think its first usage is the erroneous one, and that 
> it would have been a hell of a lot less confusing to the newbie if that usage 
> had been called 'boot' rather than 'root', because that usage actually 
> defines the drive and partition number on that drive where grub can find its 
> stage two files and the kernel and initrd to use when completing the loading 
> stage, and before you see the line "uncompressing the kernel".
> 
> That is this line in a verse of grub.conf:
>         root (hd0,0)
> which defines that its the drive normally set for master on the IDE0 cable, 
> the one on the end of the cable, thats the hd0 portion, and its the first 
> partition on that drive, which is the second 0 since all this crap runs on a 
> base zero numbering system.  It could just as easily say root (hd3,2) to 
> indicate that it would be 3rd partition in, of the drive set as slave on the 
> IDE1 cable, that is just as valid.  I haven't tried it set for an 'extended' 
> partition, and I'd assume it would take a smarter than the average bear bios 
> to handle that.
> 
> This is the usage that I would have changed, were I the one who wrote grub, 
> from root to boot, because it actually tells grub where its boot files are.
> 
> Its second usage, the argument in the kernel string, tells the kernel, in very 
> similar drive & partition syntax, where the partition to be mounted as '/' 
> is.
> 
> That is this line in a given grub verse:
> 
>         kernel /vmlinuz-2.6.23 ro root=/dev/VolGroup00/LogVol00 rhgb
> 
> And this could just as easily say root=/dev/hda7 since by this time, the 
> kernel is initializing and knows about extended partitions by then.  This to 
> me is the correct usage of the word 'root' because it truly is the root of 
> all the filesystems mounted.
> 
> But I didn't write grub, so we're stuck with the double usage of 'root' and 
> the confusion factor it creates for newbies.
> 
> AIUI, grub, if not dealing with a LVM system, can function without a /boot 
> partition, in which case the above syntax must be modified, and the grub 
> installer does this, to gave a full path like this:
> 
>         kernel /boot/vmlinuz-2.6.23 ro root=/dev/hda1
> 
> (a base 1 numbering scheme is used here, furthering the newbie confusion 
> quotient, that is equ to (hd0,0) in the other syntax)
> assuming the /boot directory is in fact available in the drive & partition 
> specified by the first usage above, but its not an optional setup I've ever 
> used and I go back to RH5.0.
> 
> Compared to lilo, grub is the handy invention similar to sliced bread or 
> bottled beer.  Where lilo is a one trick pony, grub apparently hasn't a 
> native limit in how many verses of boot setups you maintain in a 
> given '/boot' partition as I have had, by simply not deleting the older ones 
> until a 500 meg /boot partition ran out of room, as high as 28 different 
> kernels, all capable of being booted should I so desire.
> 

You make the same point I was trying to make but make it with much more
specificity.  That the same or similar words have different meanings
when used with Grub and with Linux.  That if you are working with Grub
use the Grub meanings; if you are working with Linux use that Operating
Systems vocabulary. That was what I was trying to show by talking of
Grub being a kind of separate, independent operating system. 

It can be hard on a newbie to have to keep Linux 'root' in one
compartment of the brain, while keeping the meaning of Grub 'root' in an
other compartment.  But it is not an impossible feat; humans do that
kind of thing all the time.

It is much simpler to do if you are warned ahead of time that you will
be called upon to play that mental game.  Your explanation above would
suffice to give that warning in a manual or info.
> -- 
> Cheers, Gene
> "There are four boxes to be used in defense of liberty:
>  soap, ballot, jury, and ammo. Please use in that order."
> -Ed Howdershelt (Author)

Kept your signature 'cause I love it.
-- 
Regards Bill