Abstract: Method and apparatus for serializing access to devices across multiple OS/390 systems. A subsystem intercepts device allocation requests and manages reserve/release operation of a shared control database. The control database flags allocated device as being in use, regardless of which image on which system or image reserved it. The control database can be queried by any system at anytime, preferably on a regular heartbeat basis, for information on the availability of a resource or health of a system and if a system has become non-responsive, the resource can be released for other images to use.