POWER Control by Hosts to Shared Devices Such As Direct Access Storage Devices
Original Publication Date: 1988-Jan-01
Included in the Prior Art Database: 2005-Feb-14
In a power control system with two or more groups of computer hosts feeding data to and from a group of direct access storage devices (DASD) it is conventional that only one group of hosts can control the supply of power to the DASD group. A switching unit is disclosed which enables any host group to control DASD power. In addition the switch assembly can allow any additional host to control DASD power of the same DASD group. The switching unit shown in the attached diagram allows logical data path nodes (e.g., string switch devices) to be fully supported, power-controlwise, in high-availability multi-host systems that are housed in the 9309 racking system. The unit can be housed in a 1 EIA standard unit high enclosure and can be mounted in the 9309 secondary rack in which resides the data path node.