Method of and a system for recovering data in an information processing system

A storage system coupled to a computer, comprising:

• at least one disk,
• a controller coupled to said at least one disk;
• a first physical storage area in the at least one disk;
• and
• a second physical storage area in the at least one disk;
• wherein said first physical storage area corresponds to a first logical volume accessed by said computer,
• wherein backup data is stored, said backup data being a copy of data stored in said first physical storage area at a certain time,
• wherein after said certain point in time, said controller updates data stored in said first physical storage area according to an access request to said first logical volume from said computer,
• wherein said computer upon occurrence of a failure in a process executed by said computer after said certain point in time, selects an unused second logical volume in said storage system, said second logical volume corresponding to the second physical storage area in said at least one disk, and reads the backup copy of the data made at the certain point in time and writes the backup copy to said second logical volume,
• wherein said host computer issues a swap request to said storage system, said swap request exchanging positional information of the first logical volume with that of the second logical volume, so that data of said first logical volume is interchanged with data of said second logical volume and said controller accesses said second physical storage area when said controller receives an access request to said first logical volume from said host computer,
• wherein said controller sets a value of a device busy request of said mapping information of each of said first logical volume and said second logical volume to indicate busy when said storage system receives said swap request from said computer, and
• wherein said storage system issues a device busy request to said host computer, so as to keen consistency of said first logical volume and said second logical volume, when said storage system receives an access request to said first logical volume or said second logical volume from said host computer upon processing said swap request for said first logical volume and said second logical volume.

A storage system coupled to a host computer, comprising:

• at least one disk;
• a first physical storage area in said at least one disk, said first physical storage area being included in a first logical volume accessed by said host computer,
• a second physical storage area included in a second logical volume in said at least one disk;
• and
• a controller coupled to said at least one disk;
• wherein a backup copy of data is stored, said backup copy of data being a copy of data stored in said first physical storage area at a certain point in time, and
• wherein said controller accesses said first physical storage area according to an access request to said first logical volume received from said host computer,
• wherein, after said certain point in time, when recovery of the data in the first logical volume to the certain point in time becomes necessary, said host computer selects the second logical volume in said storage system, and reads the backup copy of the data made at the certain point in time and writes the backup copy to said second logical volume,
• wherein said host computer issues a swap request to said storage system, said swap request exchanging positional information of the first logical volume with that of the second logical volume, so that data of said first logical volume is interchanged with data of said second logical volume and said controller accesses said second physical storage area when said controller receives an access request to said first logical volume from said host computer,
• wherein said controller sets a value of a device busy request of said positional information of each of said first logical volume and said second logical volume to indicate busy when said controller receives said swap request from said host computer, and
• wherein said storage system issues a device busy request to said host computer, so as to keen consistency of said first logical volume and said second logical volume, when said storage system receives an access request to said first logical volume or said second logical volume from said host computer upon processing said swap request for said first logical volume and said second logical volume.

A storage system coupled to a computer, comprising:

• at least one disk;
• first physical storage areas in said at least one disk, said first physical storage areas being included in a first logical volume accessed by said computer;
• second physical storage areas included in a second logical volume in said at least one disk;
• and
• a controller coupled to said at least one disk;
• wherein a backup copy of data is stored, said backup copy of data being a copy of data stored in said first physical storage areas at a certain point in time, and
• wherein said controller accesses one of said first physical storage areas according to an access request to said first logical volume received from said computer,
• wherein, after said certain point in time, when recovery of the data in the first logical volume to the certain point in time becomes necessary, said computer selects the second logical volume in said storage system, and reads the backup copy of the data made at the certain point in time and writes the backup copy to said second logical volume,
• wherein said host computer issues a swap request to said storage system, said swap request exchanging positional information of the first logical volume with that of the second logical volume, so that data of said first logical volume is interchanged with data of said second logical volume and said controller accesses said second physical storage area when said controller receives an access request to said first logical volume from said host computer,
• wherein said controller sets a value of a device busy request of said positional information of each of said first logical volume and said second logical volume to indicate busy when said storage system receives said swap request from said computer, and
• wherein said storage system issues a device busy request to said host computer, so as to keep consistency of said first logical volume and said second logical volume, when said storage system receives an access request to said first logical volume or said second logical volume from said host computer upon processing said swap request for said first logical volume and said second logical volume.

A method of data recovery in a storage system, said storage system including a first logical volume wherein data stored to said first logical volume is stored to first physical storage areas on one or more storage devices, said storage system including a second logical volume wherein data stored to said second logical volume is stored to second physical storage areas on said one or more storage devices, said storage system being in operative communication with a host computer that issues read and write requests to the first logical volume, the method comprising:

• storing a copy of said first logical volume at a certain point in time to a backup device as a backup copy;
• selecting, after said certain point in time, the second logical volume as a recovery target when data recovery of said first logical volume to said certain point in time is desired;
• copying the backup copy made at the point in time from the backup device and writing the backup copy to the second logical volume;
• issuing a swap request to said storage system, said swap request exchanging positional information of the first logical volume with that of the second logical volume, so that data of said first logical volume is interchanged with data of said second logical volume and said controller accesses said second physical storage area when said controller receives an access request to said first logical volume from said host computer,
• setting a value of a device busy request of said mapping information of each of said first logical volume and said second logical volume to indicate busy when said storage system receives said swap request from said host computer, and
• issuing a device busy request to said host computer, so as to keen consistency of said first logical volume and said second logical volume, when said storage system receives an access request to said first logical volume or said second logical volume from said host computer upon processing said swap request for said first logical volume and said second logical volume.