Wiping is fairly easy but if done out of order you can end up having to boot on a maintenance image such as a cd or nim. You MUST wipe the disk(s) containing the rootvg last or not at all. That being said here is the procedure:

lspv and determine the disk(s) with the rootvg. For example:

# lspv

hdisk0 00c7ae3a90d38044 rootvg active
hdisk1 00c7ae3a95f249c6 altinst_rootvg
hdisk2 00c7ae3aa367320b vg00 active
hdisk3 00c7ae3ae5ec7b97 None
hdisk4 0002c6bf97d139ad 1tb1 active
hdisk5 0002c6ff74f6f325 1tb2 active
hdisk6 0002c6ff80e12796 2tb1 active

Now that I know that hdisk0 contains the rootvg I set up a loop like this:

for x in 4 5 6 2 1 3 0 ; do
dd if=/dev/zero of=/dev/rhdisk$x bs=1m
done&

Once done the system will be unbootable.

Some systems, the "PowerPersonal" ones - 7248-1xx, do not support diags.