this dd command writes 0 bytes -- why?

[MountainX]

dd if=/dev/null of=/dev/sdX bs=446 count=1I want to remove grub from a drive while leaving the partition table in place.

when I run this on sda, dd reports 0 bytes out. I can't figure out why.

what is the right way to use this command (or similar) to remove grub?

Reference: http://ubuntuforums.org/showthread.php?t=641665

UPDATE: sda is a SCSI hardware RAID array. Ubuntu sees it as a single disk.

[amauk]

you can't read from /dev/null
you can only write to it (and all writes are discarded)

I really don't think this is a safe thing to do, but use /dev/zero instead to write null bytes

[MountainX]

Perfect! That was the fix I needed. Thank you.