Computer system and garbage collection method of disk space

A physical disk collection method of a computer system having a disk pool supply device which has a disk pool constituted by a physical disk space of one or more physical disks, a virtual volume management device which dynamically allocates the physical disk space belonging to the disk pool to a storage disk space of a virtual volume, a plurality of host computers which have a file system for managing files by using the storage disk space of the virtual volume, and a management computer for managing the host computers and the virtual volume management device, the method comprising:

• a free disk space amount acquisition step in which a free disk space amount acquisition unit of the management computer acquires a free disk space amount in the disk pool from the virtual volume management device;
• an invalid disk space amount acquisition step in which the invalid disk space amount acquisition unit of the management computer acquires in the virtual volume, from the plurality of host computers, an amount of the invalid disk space which is a disk space to which the physical disk space has been allocated but in which files are not stored;
• a determination step in which a host determination unit of the management computer determines a host computer which instructs collection of the physical disk space allocated to the invalid disk space on the basis of the amount of the invalid disk space;
• a free disk space amount judgment step in which a free disk space amount judgment unit of the management computer judges whether a free disk space amount is smaller than a predetermined threshold value which is used in a comparison with the free disk space amount of the disk pool stored in a threshold value storage section;
• a collection request step in which a collection request unit of the management computer transmits a collection request for the physical disk space allocated to the invalid disk space to the determined host computer after judging that the free disk space amount is smaller than the threshold value;
• an invalid disk space position information transmission step in which an invalid disk space position information transmission unit of the host computer generates invalid disk space position information which indicates a position of the invalid disk space in the virtual volume in cases where the collection request is received, and transmits the invalid disk space position information to the virtual volume management computer;
• and
• a collection step in which a collection unit of the virtual volume management device collects the physical disk space of the physical disk allocated to the storage disk space of the virtual volume on the basis of the invalid disk space position information.

A computer system having a disk pool constituted by a physical disk space of one or more physical disks, a disk array which dynamically allocates a physical storage space which belongs to the disk pool to the storage disk space of a virtual volume, a plurality of host computers which have a file system for managing files by using the storage disk space of the virtual volume, and a management computer for managing the host computers and the disk array, wherein

• the management computer comprises a first memory and a first processor, wherein
• the first memory stores a predetermined threshold value which is used in a comparison with the disk space amount of the disk pool, and
• the first processor acquires the free disk space amount in the disk pool from the disk array, acquires, from the plurality of host computers, an amount of the invalid disk space in the virtual volume, which is a disk space to which the physical disk space has been allocated but in which files are not stored, determines a order of the host computers which instruct collection of the physical disk space allocated to the invalid disk space on the basis of the amount of the invalid disk space, judges whether the free disk space amount is smaller than the threshold value, and transmits a collection request for the physical disk space allocated to the invalid disk space to the host computer in accordance with the determined order after judging that the free disk space amount is smaller than the threshold value;
• the host computer each comprises a second memory and a second processor, wherein
• the second memory stores written disk space position information indicating the position of storage disk space, to which the physical disk space of the virtual volume has been allocated, and file position information indicating storage disk space, in which the files of the virtual volume are stored, and
• the second processor reports the amount of the invalid disk space to the management computer and, in cases where a collection request for physical disk space which has been allocated to the invalid disk space is received from the management computer, generates invalid disk space position information indicating the position of the invalid disk space in the virtual volume on the basis of the written disk space position information and the file position information, and transmits the invalid disk space position information to the disk array;
• and
• the disk array comprises a third processor, wherein
• the third processor transmits a free disk space amount of the disk pool to the management computer and collects the physical disk space of the physical disk allocated to the storage disk space of the virtual volume on the basis of the invalid disk space position information received from the host computer.