Hugo Mills wrote:
> 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?
> :) ).
You know what, I hang my head in shame.
what you should really use for that specifically is
dd if=/dev/zero of=/dev/sda bs=446 count=1
:)
note to self:
never type answers while concentrating on other things.
Stuart
-- 
Stuart Sears RHCA etc.
"It's today!" said Piglet.
"My favourite day," said Pooh.