Re: Booting a USB hard drive
On Mon, 09 May 2011 13:21:20 -0700, Peter Bonucci wrote:
> On Monday, May 09, 2011 10:25:44 am Camaleón wrote:
>> > Booting a USB drive when the drive and computer don't cooperate is an
>> > old problem. People solved it under Debian years ago. I just don't
>> > know how they solved it and search engines didn't help.
>>
>> There shouldn't be any mistery for this. If the BIOS is capable of
>> booting from a USB device but the drive where Debian has been installed
>> is bypassed by the BIOS, I would check that:
>>
>> 1/ GRUB is installed into the MBR of the USB disk.
>
> I believe I did this while installing Debian on the USB drive. How can
> I verify it?
Last time I needed to know where was GRUB installed I used:
dd if=/dev/sda bs=512 count=1 | od -a | grep G
(where "sda" is the disk of which MBR is to be queried)
>> 2/ Partition where "/boot" is installed is marked with the bootable
>> flag (if there is no dedicated partition for "/boot", then "/" should
>> be the one to be marked).
>
> Already done. The "/" directory is marked boot.
Fine. As Arno suggests this is not usually needed but is better to do it,
just in case.
>> 3/ The system can be properly booted from an external source (i.e.,
>> using a LiveCD of SuperGrubDisk).
>
> The laptop boots from its own hard disk.
Yep, but as GRUB2 is being bypassed, we need to know if there is any
problem with GRUB2, so we are checking if it's installed in the MBR and
also if it's properly installed on the partition.
> Under SuperGrubDisk, "List devices/partitions", Grub doesn't see the USB
> drive. None of the other options boot the drive.
>
> Selecting the experimental USB support doesn't seem to change anything.
How is that? It should be accesible by SGD :-?
http://www.supergrubdisk.org/wiki/USB_Boot
But I'm starting to think the problem may be on the Western Digital USB
drive, as you said you were only facing problems with this concrete USB
disk... Look, it seems there is one report on WD forums:
How to boot linux from My passport
http://community.wdc.com/t5/My-Passport-for-PC/How-to-boot-linux-from-My-passport/td-p/74214
Greetings,
--
Camaleón
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