Storage device employing PCI-express connection solid-state drive

A storage subsystem comprising:

• a storage controller having a first processor and a second processor;
• one or more drive slots to which a hard disk drive or a solid state drive having a single port is inserted;
• a first switch and a second switch composed of a PCI-express switch having a port for supporting a downstream port containment (DPC), wherein the first switch connects the solid state drive via the port to the first processor and the second switch connects the solid state drive via the port to the second processor;
• and
• a display means for displaying whether removal of the inserted drive is enabled or not in correspondence to the drive slot in which the hard disk drive or the solid state drive is inserted;
• wherein
• when the hard disk drive is inserted to the drive slot, if power supply to the hard disk drive is stopped, the display means displays that removal of the hard disk drive is enabled;
• when the solid state drive having a single port is inserted to the drive slot, if DPC is triggered in the port of the first switch having the solid state drive connected thereto or the port of the second switch, the display means displays that removal of the solid state drive is enabled, and
• the downstream port of the first switch and the downstream port of the second switch are connected via a first link;
• when failure occurs to either one of the upstream side connection of the first switch or the upstream side connection of the second switch, DPC is triggered in the downstream port of the first or second switch on the other side of the connection where connection is normal, the downstream port of the first or second switch on the side of the connection where failure has occurred is changed to an upstream port, the DPC of the downstream port of the first or second switch on the normal connection side is cancelled, and access to the drive is enabled via the first link.