How do I initialise HDD using shell script?

[meibabe]

Hi Im new to Linux. I need to initialise 100 units of machines HDD by clearing the partition. Meaning make the HDD raw without formatting it.
I need help in getting a full script to make this work.
I was told to use

fdisk /dev/XXX <<.
o
w

or dd if=/dev/zero of=/dev/devicetoearse bs=512 count=1

but I'm not sure how to go about creating the whole script.
Any help is appreciated.
Thanks
mei

[bigtomrodney]

You're on the right track with dd, but that will only remove the partition table...the data is still on the disk as you are overwriting the first 512 bytes of the disk which is only the MBR. If you want to blank the whole disk remove the bs and count options.

If you are supposed to be wiping the machines to get rid of sensitive data I would suggest having a look at DBAN

Darik's Boot and Nuke (Hard Drive Disk Wipe)

It overwrites the data in multiple passes so that it can never retrieve. It exceeds US government requirements for disk cleansing and is really excellent.

[meibabe]

do I need to tell the script which HDD after the command
dd if=/dev/zero of=/dev/devicetoearse ?
thanks
gail

[valan]

Yes, that's it, the if option says where to get the stuff from, in this case it's /dev/zero which will output a continuous stream of zeros. The of option specifies where to write the stream to, such as /dev/sda.