On Sat, 3 Sep 2011 18:09:10 -0400 Eric Griffith egriffith92@gmail.com wrote:

Whats up guys, Was planning on re-install Arch on my laptop, started writing a couple scripts to handle the usual things I do. One of the NEW things im going to be trying is grub2. Now, the Grub2 wiki says to run

dd if=/dev/zero of=/dev/sda bs=440 count=1

to wipe out grub-legacy from the MBR.

And since the Arch-devs removed "No Bootloader" as an option in the AIF, you can't follow the "during installation" instructions for Grub2.

Here's my problem, just by sheer luck was I roaming the web today, and noticed a few other threads (in various forums for various distros / blogs) and they all had a similar command to run if youre grub-legacy was screwed and you needed to write over it. The only issue, and the reason for this email? They had different commands.

Not completly different, but different enough that raised an eyebrow. In

dd if=/dev/zero of=/dev/sda bs=440 count=1

They had various numbers for bs=, some 440, some 446, some 506, and some 512. Normally I would've just shrugged and followed the wiki, but notice on one said that if you zero out too far, you wipe out hte partition table...which I wouldn't enjoy haha.

So can anyone confirm that the command above, from the wiki, is correct? And that it IS 440, and not something different. I'd hate to pick the wrong one and zero out my partition table, or not completly zero out grub-legacy and run into a whole different set of problems.

Thanks!

grub gets installed in the first 440 (446) bytes, then some disk-specific data (optional), the rest takes up the partition table up to the 512th byte. look also at https://secure.wikimedia.org/wikipedia/en/wiki/Master_boot_record