Re: [Hampshire] Removing MBR

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Author: Hugo Mills
Date:  
To: Hampshire LUG Discussion List
Subject: Re: [Hampshire] Removing MBR

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On Tue, Jun 10, 2008 at 02:08:52PM +0100, Stuart Sears wrote:
> Rob Malpass wrote:
> >Hi all
> >
> >I'm trying to resurrect an old PC and install an old distribution on it.
> >Said PC isn't good enough to be considered anything but an sftp server
> >(it's around 1999 vintage). Problem is - I can't get past whatever was
> >in the master boot record before. All I get in fact at bootup is "LI"
> >- then it hangs.
> >
> >I know that I can get around this by booting from a DOS disk and doing
> >fdisk /mbr. However - out of interest - if I didn't have an MSDOS boot
> >disk - how would I do this?
> >
> >I'm putting slackware 7.1 on it and in booting from that cdrom, I can't
> >get fdisk /mbr to work. I can't find anything in the fdisk options
> >which is anything to do with the mbr.
>
> wipe it or fix it?
>
> dd if=/dev/zero of=/dev/sda bs=521 count=1


512, not 521...

> Writing more than 512 bytes to the MBR is also fine, unless you have
> partitions you would like to preserve. :) (trust me, you don't want to
> do that).
>
> That will wipe the MBR.


Writing 512 bytes will also overwrite the partition table, so
you'll lose the positions of the partitions. More than 512 bytes *may*
start overwriting the start of the filesystem on the first partition
(but then, you've just lost the location of that, so what do you care?
:) ).

Hugo.

-- 
=== Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk ===
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