Re: swapping master & slave HDs: dd bs=446

[Alvin Oga <aoga@ns.Linux-Consulting.com>]

hi ya spamhog  ( cute )

On 4 Oct 2004, SpamHog wrote:

> Interesting point: what's in bytes 447 and 448?

- the boot records ( MBR ) is 512 bytes total
 
- there is only 4 primary partitions ... each is 16 bytes
	( 64 bytes is the total number of bytes needed to 
	( define your primary partitions 
	( logical boot info is stored elswhere

- a bootable partition ( if it is used/set ) is aa55 ( 2 more bytes )

512 - 64 -2 is 446 

to create a bootable without using grub/lilo/syslinux/loadlin...

	# dd if=/dev/hda of=/dev/hdc bs=446 sync

	where /dev/hda is a working boot disk

	where /dev/hdc is a new disk you want to start booting off of
	before making /dev/hda go bye-bye

c ya
alvin