Method for managing hard disk drive expanders in a cluster storage system

A method for managing hard disk drive (HDD) expanders in a cluster storage system, the cluster storage system further including a host computer connected to the HDD expanders to form a hierarchical tree structure, the method comprising steps, to be implemented by each of those of the HDD expanders that are connected indirectly to the host computer, of:

• upon receiving a device-type request for inquiring a device type from a parent node of the HDD expander in the hierarchical tree structure, determining whether the device-type request originates from the host computer;
• when it is determined that the device-type request originates from the host computer, transmitting a device-type reply indicating a device type not of HDD expander to the host computer;
• and
• when it is determined that the device-type request does not originate from the host computer, transmitting a device-type reply indicating a device type of HDD expander to a node that initiates the device-type request, and forwarding the device-type request to each child node of the HDD expander in the hierarchical tree structure.

A cluster storage system comprising:

• a host computer;
• and
• a plurality of hard disk drive (HDD) expanders connected to said host computer to forma hierarchical tree structure, said host computer serving as a root node of the hierarchical tree structure,
• wherein said HDD expanders are configured in one of a first configuration and a second configuration,
• wherein, in the first configuration, each of said HDD expanders is configured to
• upon receiving a device-type request for inquiring a device type from a parent node of said HDD expander in the hierarchical tree structure, determining whether the device-type request originates from the parent node,
• when it is determined that the device-type request originates from the parent node, transmitting a device-type reply indicating a device type of HDD expander to the parent node, and forwarding the device-type request to each child node of said HDD expander in the hierarchical tree structure, and
• when it is determined that the device-type request does not originate from the parent node, transmitting a device-type reply indicating a device type not of HDD expander to the parent node,
• wherein, in the second configuration, each of those of said HDD expanders that are connected indirectly to said host computer is configured to
• upon receiving a device-type request for inquiring a device type from a parent node of said HDD expander in the hierarchical tree structure, determining whether the device-type request originates from said host computer,
• when it is determined that the device-type request originates from said host computer, transmitting a device-type reply indicating a device type not of HDD expander to said host computer, and
• when it is determined that the device-type request does not originate from said host computer, transmitting a device-type reply indicating a device type of HDD expander to a node that initiates the device-type request, and forwarding the device-type request to each child node of said HDD expander in the hierarchical tree structure.