During a system decommission process, it is advisable to format or at least erase all drives. There are 2 ways of accomplishing that:
If you have time:
AIX allows disks to be erased via the Format media service aid in the AIX diagnostic package. To erase a hard disk, run the following command:
# diag -T format
This will start the Format media service aid in a menu driven interface. If prompted, choose your terminal. You will then be presented with a resource selection list. Choose the hdisk devices you want to erase from this list and commit your changes according to the instructions on the screen.
Once you have committed your selection, choose Erase Disk from the menu. You will then be asked to confirm your selection. Choose Yes. You will be asked if you want to Read data from drive or Write patterns to drive. Choose Write patterns to drive. You will then have the opportunity to modify the disk erasure options. After you specify the options you prefer, choose Commit Your Changes. The disk is now erased. Please note, that it can take a long time for this process to complete.
If you want to do it quick-and-dirty:
For each disk, use the dd command to overwrite the data on the disk. For example:
for disk in $(lspv | awk '{print $1}') ; do
dd if=/dev/zero of=/dev/r${disk} bs=1024 count=10
echo $disk wiped
done
This does the trick, as it reads zeroes from /dev/zero and outputs 10 times 1024 zeroes to each disk. That overwrites anything on the start of the disk, rendering the disk useless
