Just a thought ... you're not trying to share DASD between the z/OS (MVS) systems in a, 'risky' way, are you?
(Even more bizarre thought - you're not trying to share paging volumes between your z/VM systems, are you? This would certainly provide many opportunities for virtual machines to crash in peculiar ways. I once accidentally shared a page dataset between two OS/VS1 systems - I can state categorically, it does not work!) Jeff