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On 01/15/2014 02:42 PM, Alexei Kornienko wrote:
> If you are working on linux system following can help you:
> 
> dd if=/dev/urandom of=/dev/sda bs=4k

That's going to be slow.
The shred tool should be already installed on most Linux systems,
and uses an internal PRNG to write either zeros or random data in a fast manner.

The cinder LVM driver has support for this already as an option,
by setting volume_clear=shred. That defaults to writing a random
pattern _3 times_.

Depending on your requirements, writing zeros might suffice,
in which case the default volume_clear=zero functionality
which uses dd if=/dev/zero ... could be used.

thanks,
Pádraig.