[PLUG-TALK] Netbook computer disassembly

[Galen Seitz]

On 11/23/16 15:08, Rich Shepard wrote:
> On Tue, 22 Nov 2016, Paul Mullen wrote:
> 
>> Any idea what partitition table scheme is used on the SSD?  Modern
>> hardware mostly uses GPT, with which, says the Internet, LILO has
>> occasional difficulty:
> 
>    This, apparently, is the source of the problem. When I first installed
> Slackware-14.2 cfdisk offered me a table of partition types and I selected
> gpt because that's what worked on the two 64-bit portables (using lilo).
> It apparently does not work on a 32-bit system using lilo.
> 
>    My web searches inform me that the only tool that will remove the gpt at
> the end of the disk and replace it with a dos partition table in the MBR at
> the head of the disk is a tool called gdisk.
> 
>    The gdisk page leads to the downloadable source on sourceforge.net. But,
> the only downloadable file there is gdisk_1.0.1-1_amd64.deb. My system has a
> 32-bit Intel Atom CPU, not a 64-bit AMD. I think there's a tool to convert
> .deb files to .tgz files but that won't make gdisk compatible with my
> system.
> 
>    Are there other ways to remove the gpt and give me a clean SSD so I can
> start over?

Honestly, I think you would be better off in the long run if you took
the time to learn to use grub and gpt.  That said, dd is your friend.
You can write anywhere on the disk you like.  Because you can write
anywhere, dd is also very dangerous.  Make sure you know what you are doing.

If the current contents of the disk are unneeded, then *something* like
the following should work.

Wipe the first megabyte
dd if=/dev/zero of=/dev/destination_disk count=1 bs=1M

Now determine the size of your disk in your granularity of choice.  You
probably know how many 512 byte sectors there are, since you've been
messing about with partitioning.

N = number of 512 byte sectors (a very large number)


Now let's wipe the last ~5MB of disk.

M = N - (5 x 2048) = N - 10240

dd if=/dev/zero of=/dev/destination_disk seek=M bs=1b count=10240


Be certain you are giving dd the proper of=... argument.  Please review
the dd man page too.  I'm not responsible for lost data.


galen
-- 
Galen Seitz
galens at seitzassoc.com