Wipe the disk

There’s no guaranty that you data cannot be retrieved after erasing/cleaning data, or any level of formatting your disk, probably even with writing zeros. That’s why in some cases with very sensitive data, the disks must be mechanically destroyed.

But simple rewriting with new non-important stuff on top of your previous contents, doesn’t leave much chances (if not at all) to somebody to guess what was written before.

Bob, I'm not sure if /dev/zero exists on AIX, but you can use the dd command to write arbitrary blocks of data across the entire disk(s).

Try dd if=/dev/zero of=/dev/dsk/cXtXdXsX bs=8k count=Y

where Y is the size of the disk in kilobytes divided by 8. of is the output file you want to write to.

You'll want to do this from install media or another host if you are "zeroing" the data of the boot/root disk.