Re: what is the device.map used for ?

[adrian15]

John Lumby wrote:
> Not a bug, not even a problem - just curious.
>
> I understand what the device.map is and how to specify it,  but I have 
> yet to come across something that uses it; 

When you boot and grub appears device.map has no sense. hd0 is the first 
hard disk given by the bios, hd1 is the second... and so.

If you're under a unix/gnu/linux environment grub needs to know which 
linux device correspond to which grub device.

If no device.map exists grub says: Trying to guess BIOS devices... this 
may take some time.
You can edit the device.map but usually is created when installing the 
distro, anaconda, creates it.

When you run grub there's an option to select another device.map file... 
you know it can be: my_own_device.map.

When you run grub there's an option so that it does not read any 
device.map file.

And there's the command (only inside the grub shell under a linux 
environment) you suspected which's name is device.

device (hd0) /dev/hda

maps the /dev/hda disk to (hd0) and it overrides what you already 
specified with the device.map or another device command.


Usign the device command (or editing device.map) is useful for 
installing grub in pendrives,... because pendrives devices are not 
usually included on device.map files.

adrian15