There is a CYL0_BLK0_CLEANUP setting, and if you set it to YES, it will scratch mdisks that start at cyl 0 too.
Or if you have, like we once suffered from, an admin guy who found it more secure to use the option CLEAN on the PURGE or DMDISK commands, overriding the default dirmaint settings, well we lost the same system twice, before we realized that someone else had an userid with fullpack minidisk overlays removed as he was no longer responsible and we were sure we had Dirmaint configured with CYL0_BLK0_CLEANUP=NO ...... Ronald van der Laan
