Re: boot fails on wheezy (SOLVED)

["Goh Lip" <g.lip@gmx.com>]

On Tue, 04 Jun 2013 17:09:15 +0800, Pierre Frenkiel  
<pierre.frenkiel@gmail.com> wrote:

> On Tue, 4 Jun 2013, Goh Lip wrote:
>
> > The allocation of disk numbering (sda, sdb...or (hd0, hd1...) is done  
> > by bios and the OS will use whatever the bios determine.
> > Also this numbering is not consistent with each reboot.
> >
> > We should always set "master" and "slave" for jumper wires or use  
> > correct primary or secondary cabling (but if you have 1 master and 2  
> > slaves, the slaves will continue to be changeable).
> >
> > And...use grub2. Grub-legacy 'calls out' partition using (hdx,y) or  
> > sdxy whereas grub2 'searches' using UUID.
> >
> > fstab had changed to UUID from sdxy years ago to overcome problems like  
> > this.
>
>    hi Goh,
>    I don't understand the relation between my question and your answer:
>    the problem was with the BIOS boot sequence, and as far as I know,
>    this is totally independant of any OS.
>    the boot sequnce, which was since the installation, several years ago:
>
>      1 dvd drive
>      2 ST3250410AS
>
>      and I found it has been replaced with:
>      1 dvd drive
>      2 ST3750640AS
>
>   and the problem disappeared, without any change in grub,
>   as soon as I reverted to the original BIOS  boot sequence
>
>   So, my question is still: how can a boot sequence change, without  
> entering
>   into BIOS at boot.
>
> best regards,

Okay, understood what you mean.

Your bios did not detect both drives and the first drive it detected was  
put into the boot sequence.
Still, if having both drives set as "master" may confuse the bios, so it  
is better to check if the drives are differentiated by "master" and  
"slave" through jumper wires (ide) or primary/secondary cabling (sata).  
Mixing ide and sata drives can also confuse the bios.

Also, it is always better that booting is determined by UUID rather than  
/dev/sdxy or (hdx,y). And grub2 in this respect is better than grub-legacy.

Hope this explains.
Cheers.


--
I used to have an open mind,
but my brains kept falling out.