SERVER DIRECT ATTACHED STORAGE SHARED THROUGH VIRTUAL SAS EXPANDERS

PURPOSE: A storage device for directly connecting a server shared through a virtual SAS expander is provided to enable bidirectional traffic to corresponding connection disks and other nodes. CONSTITUTION: A first server includes first storage disks storing data, and a first HBA(Host Bus Adapter)(102a) including a first virtual expander(116a) and a first processor which provides a first logic component. The second server includes second storage disks storing the data, and a second HBA(102b) including a second logic component and a second processor which provides a second virtual expander(114b). The first HBA is combined with the second HBA through an SAS(Serial Attached Small Computer System Interface) connection unit, and the first and second storage disks are accessed by the first and second servers. [Reference numerals] (100) System #1; (110,210) Internal drives; (114a,116b,214a,216b) PCI/HBA logic; (114b,116a,214b,216a) Virtual expander; (118,218) PCI bus; (200) System #2; (AA,DD) External SAS cables(looped to a last machine); (BB,EE) External SAS cable; (CC,FF) External SAS cable(to additional machine(s))