lilo vs grub

[Pekka Savola]

On 21 Oct 2003, Alexandre Oliva wrote:
[...]
> Now let's go back to the industrial bioses you mentioned.  Ok, hda
> failed, so the bios tries hdc.  lilo has to know it has to load from
> hdc as well, right?  But how does it know which number it should use?
> If it reads from disk 0x80, it may get failures for reading from hda,
> or it may be getting sectors from the remapped hdc.  Now assume it got
> it right, and worked.  But then, I want to replace the broken hda.  So
> I insert a new disk there, and voila, can't reboot.
[...]

Uhh.. is this really a problem?  If you re-add a disk after a failure, I'd 
suppose the user would be intelligent enough to change the boot sequence 
in the bios to actually skip hda :-).  Of course, if there is no useful 
data to use for booting on HDA (e.g. brand new drive), the BIOS will just 
skip it and try the next drive in the boot order.

Around RHL 6.1 or so (2-3 years ago), I did a lot of experimenting with
software-RAID1 on root partition, including plugging off hda, doing some
hard drive power disconnecting on the flight etc. -- it worked just fine
once you had figured out how to get lilo installed properly on both the
drives. When I removed hda drive, lilo would get booted up from hdc
without any user interaction.

IMHO, it's not *in practice* such a complex thing, I think!

-- 
Pekka Savola                 "You each name yourselves king, yet the
Netcore Oy                    kingdom bleeds."
Systems. Networks. Security. -- George R.R. Martin: A Clash of Kings