Storage device and method for managing size of storage device

A method for managing the size of a storage device (10) comprising:

• providing the storage device (10) that has a processor (205), a root complex (206) connected to the processor (205) and including a root port (207), an interface device including an endpoint (200, 201, 202), and a switch (100) that mutually connects the root port (207) and the interface device, wherein
• the switch includes:
• a first port (P00) connected to the root port (207), a second port (P04, P05, P06) connected to the endpoint (200, 201, 202), a plurality of cross-link ports (P01, P02) that are mutually connected with a cross-link (303),
• a virtual switch (VS0, VS1) for connection to the root port, the virtual switch (VS0, VS1) having an upstream bridge (101) connected to the root port (207), and
• a virtual switch (VS2, VS3) for connection to the cross-link, the virtual switch (VS2, VS3) having an upstream bridge (101) connected to the cross-link (303),
• the method being adapted to add, to the storage device (10) in operation, in which the processor (205) controls the interface device by accessing the endpoint (200, 201, 202) via a path that passes through the root port (207), the first port (P00), and the second port (P04, P05, P06), and a path that passes through the root port (207), the first port (P00), the cross-link (303), and the second port (P04, P05, P06), one or more add-on storage devices (11) each having the same configuration as the storage device (10) and having the same number of or a different number of endpoints as/from the storage device (10), the method comprising:
• causing the processor (205) of the storage device (10) to, in response to an instruction to add the storage device (11), hot-remove a PCI function (204) of the endpoint (200, 201, 202) that is accessed from the virtual switch (VS2, VS3) for connection to the cross-link,
• causing an MR-PCIM of the storage device (10) to, in response to an instruction to remove the cross-link connection of the storage device (10), update a global key, which contains information to identify a virtual hierarchy, of the virtual switch (VS2, VS3) for connection to the cross-link whose cross-link has been removed and a global key of the PCI function (204) that has been hot-removed with a global key representing a virtual hierarchy used in the add-on storage device (11),
• causing the MR-PCIM of the storage device (10) to, in response to a connection between the cross-link ports (P01, P02) of the storage device (10) and cross-link ports (P11, P12) of the add-on storage device (11), recognize a switch (500) and an end-point (504) of the add-on storage device (11),
• causing the processor (205) of the storage device (10) to hot-add a PCI function (505) of the endpoint (504) that is accessed using a virtual switch (VS6, VS7) for connection to the cross-link of the add-on storage device (11), and
• causing a processor of the add-on storage device (11) to hot-add the PCI function (505) of the endpoint (504) that is accessed using a virtual switch (VS4, VS5) for connection to a root port of the add-on storage device (11) and to hot-add the PCI function (204) of the endpoint (200, 201, 202) that is accessed using the virtual switch (VS2, VS3) for connection to the cross-link of the storage device (10).