Re: man page for grub-probe

[Felix Zielcke]

An average user should only ever need to run grub-install and
grub-mkconfig, but nothing else.

Am Donnerstag, den 24.09.2009, 11:39 +0100 schrieb ael:
> As a new potential user of grub2, even after scanning the grub2 wiki, I 
> find the man page for grub-probe incomprehensible.
> 
> 1) -d, --device
>                given argument is a system device, not a path
> 
> Ok, so what does "system device" mean in this context? 
system device means the device of your operating system
On Linux for example grub-probe -d /dev/sda

> 
> 2)
> # grub-probe  /dev/fd0
> grub-probe: error: Cannot open `/boot/grub/device.map'
> 
> So how is the device map created? And is  /boot/grub/device.map being 
> sought on the /dev/fd0 file system? Presumably not.

grub-install takes care about creating device.map if it doestn't exist
yet.
If it does already then either call grub-install with --recheck or
directly grub-mkdevicemap
grub-probe just told you above where it expected the file.
All GRUB utilities use always the files on the mounted /boot/grub by
default, except if you give them with their options other files/paths.

> 
> 3) -t, --target=(fs|fs_uuid|drive|device|partmap|abstraction)
>                print filesystem module, GRUB drive,  system  device, 
> partition
>                map module or abstraction module [default=fs]
> 
> So I tried
>    # grub-probe -v -t /dev/fd0 /dev/fd0
> and just got:
> 
> Try ``grub-probe --help'' for more information
> 
> Of course, --help gave no help :-)

It does, but you seem to fail to understand the GNU way (or is it even
generic UNIX way?) of telling how to use options.
You can use, either of these _without_ replacing anything with /dev/fd0
or stuff like that:
-t fs
-t fs_uuid
-t drive
-t device
-t partmap
-t abstraction
> 
> I could go on, but I hope that the point is clear. As a new user, who 
> even has a small amount of experience with several boot loaders, but who 
> only needs to look at them rather infrequently, I am lost here.
> 
> OK with lots of time and searching and probably needing to install and 
> read source, I will probably eventually fathom what is needed, but just 
> a few extra lines in the man page might make all of that unnecessary.
> I would offer to a patch, if only I knew what those extra lines should 
> be :-)
> 
> ael


-- 
Felix Zielcke
Proud Debian Maintainer