[ILUG] New drives getting recognized as device mapper devices

[A. Dreyer]

Walter Faleiro wrote:
> 
>     Achim,
> 
> I want to use the drives anew.
> 
> I had run fdisk and deleted all the partitions on it and after rebooting
> it still shows device-mapper info.
> Will the below command clear all information on the drive if I run it
> after deleting the current partitions? Or is there more configuration
> after it.
> 
> Regards,
> --Walter

It should not matter if you already have removed the partitions with
fdisk. From the described the disk layout looked like one large
partition per disk - even if you delete and recreate the partition the
partition data is most likely not overwritten, so the LVM or dm label
might be intact. To make sure that the disk label, the partition table
and the partion label is blanked run for disk sdb:

   # dd if=/dev/zero of=/dev/sdb bs=1M count=8

which writes 8MB of zero's over this area. After that you need to
re-label and re-partition the disk.


Regards,
Achim

--
Achim Dreyer                || http://www.adreyer.com/
Senior Unix & Network Admin || RHCE, RHCA, CCNA, CCSA, CCSE, CSCE
Phone: +44 7756 948229      || CACert assurer