[gentoo-user] Re: How can I rewrite all empty sectors with zeros?

[Nikos Chantziaras]

On 22/07/12 20:18, Jarry wrote:
Hi,
I want to backup my whole hard-drive (8 partitions) with:
# dd if=/dev/sda | gzip > /path/image.gz
In order to achieve good compression level I'd like to wipe
out all empty space with zeros. How can I do that?

That's the wrong way to do it.  You should use a tool that only copies 
the data, and then also backup the partition table.

Or use partimage/clonezilla like Neil mentioned which does all that 
automatically.