Multi-path computer system

An apparatus connected with input/output devices having a plurality of access areas, by a plurality of paths, comprising:

• a plurality of host adapters connected with said plurality of paths and performing access to the input/output devices;
• access path information indicating areas of the input/output devices accessible by each of said plurality of host adapters;
• a multi-path control part selecting a specific host adapter, according to the access path information, when access is made by a software operating in said apparatus to a specific area of the input/output devices;
• and
• a path determining part determining properness of said plurality of paths, by using identification information comprising device information and area information responded by said input/output devices, and the access path information.

An input/output device connected with at least one host apparatus via a plurality of paths, comprising:

• a plurality of areas to which access can be made from the host apparatus;
• area information corresponding to said plurality of areas, respectively;
• device information for identifying said input/output device;
• a channel adapter which is connected with said plurality of paths, and permits or inhibits, for each area, access from the host apparatus, according to the area information;
• and
• an identification information responding part responding to the host apparatus by identification information comprising the device information and area information.

A multi-path computer system in which at least one host apparatus and at least one device are connected via a plurality of paths,

• the device comprising device information for identifying said device, channel-adapter number information unique in said device, and a channel adapter connected with said plurality of paths, and permitting/inhibiting access from the host apparatus;
• the host apparatus comprising a plurality of host adapters connected with said plurality of paths and performing the access to the device;
• access path information indicating areas of the device accessible from each of said plurality of host adapters;
• and a multi-path device control part selecting a specific host adapter according to the access path information at a time of access to a specific area of the device;
• and
• said channel adapter responding to the host apparatus by identification information comprising the device information and channel-adapter number information;
• and said host apparatus providing the identification information concerning an error path to the other multi-path control parts of their own apparatus or the multi-path control parts of the other apparatuses, when detecting the error path.

An apparatus connected with devices via a plurality of paths, comprising:

• a plurality of host adapters connected with said plurality of paths and performing the access to the devices;
• access path information indicating areas of the devices accessible from each of said plurality of host adapters;
• a multi-path control part selecting a specific host adapter according to the access path information at a time of access to a specific area of a device;
• and
• a part informing of identification information, concerning an error path, comprising device information and channel-adapter number information of a device responded from said device, to the other multi-path control parts of their own apparatus or the multi-path control parts of the other apparatuses, when detecting the error path.

A device connected with at least one host apparatus via a plurality of paths, comprising:

• device information for identifying said device;
• channel-adapter number information unique in said device;
• a channel adapter connected with said plurality of paths, and permitting/inhibiting access from the host apparatus;
• and
• an identification information responding part responding to the host apparatus by identification information comprising the device information and channel-adapter number information.

A multi-path computer system in which at least one host apparatus and at least one device are connected via a plurality of paths,

• the device comprising device information for identifying said device, component exchange-unit information for said device, and a channel adapter connected with said plurality of paths, and permitting/inhibiting access from the host apparatus;
• said host apparatus comprising a plurality of host adapters connected with said plurality of paths and performing the access to the device;
• access path information indicating areas of the device accessible from each of said plurality of host adapters;
• and a multi-path device control part selecting a specific host adapter according to the access path information at a time of access to a specific area of the device;
• and
• said channel adapter responding to the host apparatus by identification information comprising the device information and component exchange-unit information;
• and said host apparatus terminating operation concerning a path employing a channel adapter, and, also, providing the identification information concerning said channel adapter to the other multi-path control parts of their own apparatus and/or the multi-path control parts of the other apparatuses, when a request of exchanging said channel adapter is given.

An apparatus connected with devices via a plurality of paths, comprising:

• a plurality of host adapters connected with said plurality of paths and performing the access to the devices;
• access path information indicating areas of the devices accessible from each of said plurality of host adapters;
• a multi-path control part selecting a specific host adapter according to the access path information at a time of access to a specific area of a device;
• and
• a part terminating operation concerning a path employing a channel adapter, and, also, providing the identification information, concerning said channel adapter, comprising device information and component exchange-unit information responded from the device, to the other multi-path control parts of their own apparatus and/or the multi-path control parts of the other apparatuses, when a request of exchanging said channel adapter is given.

A device connected with at least one host apparatus via a plurality of paths, comprising:

• device information for identifying said device;
• component exchange-unit information for said device;
• a channel adapter connected with said plurality of paths, and permitting/inhibiting access from the host apparatus;
• and
• an identification information responding part responding to the host apparatus by identification information comprising the device information and component exchange-unit information.

A computer readable recording medium, having a program for a computer to perform a process of a host apparatus of a multi-path computer system in which at least one host apparatus and at least one device are connected via a plurality of paths, recorded therein, said program comprising:

• first program code means for obtaining, from a channel adapter of the device, device information of said device, area information corresponding to a plurality of accessible areas of said device, channel-adapter number information for said device, and/or component exchange-unit information for said device;
• second program code means for determining properness of the plurality of paths, from access path information and identification information comprising the device information and area information;
• third program code means for providing identification information, concerning an error path, comprising the device information and channel-adapter number information, to the other multi-path control parts of their own apparatus or the multi-path control parts of the other apparatuses, when detecting the error path;
• and
• fourth program code means for terminating operation concerning a path employing a channel adapter, and, also, providing identification information, concerning said channel adapter, comprising the device information and component exchange-unit information, to the other multi-path control parts of their own apparatus and/or the multi-path control parts of the other apparatuses, when a request of exchanging said channel adapter is given.