Re: How to get rid of an entry in grub?
David Guntner <david@guntner.com> writes:
> Joe Pfeiffer grabbed a keyboard and wrote:
>> David Guntner <david@guntner.com> writes:
>>
>>> Hugo Vanwoerkom grabbed a keyboard and wrote:
>>>> David Guntner wrote:
>>>>> Hmmm..... I wonder if the MBR for the drive sill has a loader on it,
>>>>> even though I removed all partitions and repartitioned it? Is there a
>>>>> utility out there that can wipe the MBR of a drive without touching the
>>>>> rest of the contents?
>>>>
>>>> There is http://bootinfoscript.sourceforge.net/ also.
>>>
>>> Ok, I got that, thanks. Ran it and it does look like there's a remnant
>>> of the old 6.0 system that lived on that drive at one time.
>>>
>>> So, how to *wipe* the MBR for that drive without losing everything on
>>> it? :-) Is there a way?
>>>
>>> 'Cause face it, if I get rid of the boot record on the drive, grub won't
>>> see it anymore even without my disabling the probe script. :-)
>>
>> That is the cleanest way to do it!
>>
>> Looking around a bit, I found the following:
>>
>> https://bbs.archlinux.org/viewtopic.php?id=119702
>>
>>
>> The command to do it was
>>
>> $sudo dd if=/dev/zero of=/dev/sdx bs=446 count=1
>>
>> Something the poster didn't emphasize strongly enough (IMHO) is that
>> he's only wiping the first 446 bytes of the MBR -- this leaves the
>> partition table alone.
>
> Seems like a good idea. I tried it, but it doesn't look like it worked:
>
>> # dd if=/dev/zero of=/dev/sdb bs=446 count=1
>> 1+0 records in
>> 1+0 records out
>> 446 bytes (446 B) copied, 0.000867678 s, 514 kB/s
>> # update-grub
>> Generating grub.cfg ...
>> Found background image: /usr/share/images/desktop-base/desktop-grub.png
>> Found linux image: /boot/vmlinuz-3.2.0-4-amd64
>> Found initrd image: /boot/initrd.img-3.2.0-4-amd64
>> Found memtest86+ image: /memtest86+.bin
>> Found memtest86+ multiboot image: /memtest86+_multiboot.bin
>> Found Debian GNU/Linux (6.0.7) on /dev/sdb1
>> done
>
> Grub still seems to think there's Linux on /dev/sdb1. That's
> aggravating...... I guess I'll just try moving the stuff off of the one
> and only partition on that drive to somewhere else temporarily, and then
> delete the partition outright and recreate it. Maybe *THAT* will
> finally do it!
>
> --Dave
Ah, I missed that it was on a partition (and not the MBR). What
*should* work is
$sudo dd if=/dev/zero of=/dev/sdb1 bs=512 count=1
More information:
http://www.novell.com/documentation/suse91/suselinux-adminguide/html/ch07.html
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