JP2004171597A - Storage device system of preparing copy of data - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prepare a copy of a dataset or file in a storage device. <P>SOLUTION: A control device 112 receives from a host 100 a volume including original data (an original volume), a volume storing a copy (a copy volume), and a start address and an end address indicating a range of an objective dataset or file. The control device 112, depending on the received information, reads from a storage device 113 the data of the objective range in the original volume, and prepares the copy. <P>COPYRIGHT: (C)2004,JPO

Description

  The present invention relates to a storage system in an information processing system or the like, and more particularly to a computer system having a function of creating a copy of data stored in a volume.

It is generally known to take a backup as a means for preventing important data from being completely lost when a failure occurs in a storage device. Normally, in order to guarantee the consistency of the data to be backed up, the read / write processing for the volume is stopped while the backup is being taken. For this reason, there is a problem that the process using the volume to be backed up must be stopped while the backup is being performed. To solve this problem, a copy of the volume is created in the storage device, and (1) usually matches the original volume data with the data of the copy volume. (2) During the backup, the original volume data is copied. It is known that the data does not match the data of the copy volume (therefore, the copy volume represents the original volume at a certain point in time), and (3) the backup uses the copy volume. ing. As a result, consistent data can be taken as backup data without stopping the processing while the backup is being taken.

  In the above method, since the unit for making a copy is a volume, it is necessary to make a copy of the entire volume even when data of a specific area (for example, a data set or a file) in the volume is required. is there. Therefore, unnecessary copying occurs, and there is a problem that (1) extra load is applied to the storage device, and (2) extra time is required.

  Generally, in a storage device, since the structure of a file system managed by a host is not known, it is not known which area a data set or file is composed of. In the present invention, means for notifying the storage device of the area from the host is provided. Using this means, the storage device makes copies of areas such as data sets and files as originally required to reduce unnecessary load and time.

  Since copying of data sets, files, and the like in units of area is enabled, unnecessary copying can be reduced. As a result, the load on the storage device and the time for making a copy can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the present embodiment.

  FIG. 1 is a system configuration diagram showing a first embodiment of the present invention. The system includes a host 100, a control device 112, and a storage device 113. The host 100 issues various requests to the control device 112 according to a user's instruction or a user program. The storage device 113 stores data. The control device 112 reads data from the storage device 113 or writes data to the storage device 113 according to a request from the host 100.

The control device 112 includes a control processor 101, a control memory 109, and a cache memory 111.

The control processor 101 controls the control device 112. In the control processor 101, a pair creation process 102, a pair split process 103, an extent update process 104, a write process 105, a pair creation copy process 106, a pair split copy process 107, and an extent update copy process 108 operate. The control memory 109 stores control information necessary for the control processor 101 to control the control device 112, for example, pair information 110. The cache memory 111 temporarily stores data received from the host 100 and data read from the storage device 113.

  FIG. 2 shows the data structure of the pair information 110. The pair information 110 includes a use flag 200, a primary volume number 201, a secondary volume number 202, a pair status 203, difference information 204, and extent information 205. The use flag 200 is a flag indicating whether the pair information 110 is used, that is, whether the information in the pair information 110 is valid. 1 indicates valid, and 0 indicates invalid. The primary volume number 201 indicates the number of the original volume when a copy of the volume is created in response to a request from the host 100. The secondary volume number 202 is the number of the volume that stores a copy of the data of the original volume when a copy of the volume is created in response to a request from the host 100. The pair status 203 indicates how far the process of creating a copy of the volume has progressed, and has four values of “being formed”, “being formed”, “being split”, and “being split”. The difference information 204 is information indicating that data differs between the volume indicated by the primary volume number 201 and the volume indicated by the secondary volume number 202. The extent information 205 is information indicating where an area such as a data set or a file is stored in the volume, and includes a use flag 206, a start address 207, and an end address 208. The use flag 206 is a flag indicating whether or not the extent information 205 is valid. 1 indicates that the extent information 205 is valid, and 0 indicates that it is invalid. The start address 207 is an address indicating the start of an area such as a data set or a file, and the end address 208 is an address indicating the end of an area such as a data set or a file.

  FIG. 3 shows the structure of the difference information 204. The difference information 204 is composed of three types of bitmaps, that is, the creating difference information 300, the dividing difference information 301, and the updating difference information 302. One bit corresponds to one track, and when the value is 0, it indicates that the data of the corresponding track matches the volume indicated by the primary volume number 201 and the volume indicated by the secondary volume number 202, When the value is 1, it indicates that they do not match. Of course, one bit may be applied to another unit.

  FIG. 4 shows a processing flow of the pair creation processing 102. The host 100 issues a pair creation request when the control device 112 creates a copy of a certain volume. When receiving the pair creation request from the host 100, the control processor 101 starts the pair creation processing 102. The pair creation request has two parameters.

  A volume number of a volume for creating a copy (this volume is called an original volume) and a volume number of a volume for storing copy data (this volume is called a copy volume).

In step 400, the unused pair information 110 whose use flag 200 is 0 is selected, the use flag 200 is set to 1, and the volume number of the original volume received from the host 100 is set to the primary volume number 201. Then, the volume number of the copy volume received from the host 100 is set to the secondary volume number 202, the pair status 203 is set to “being formed”, and all the bits of the creating difference information 300 of the difference information 204 are set to “1”. , 0 is set to all bits of the difference information 301 during division, 0 is set to all bits of the difference information 302 during update, and 0 is set to the use flag 206 of the extent information 205. In step 401, the pair creation copy process 106 is started and ends.

  FIG. 5 shows a processing flow of the pair division processing 103. The host 100 issues a pair split request to the control device 112 when the data stored in the copy volume is determined and the data stored in the copy volume can be used. When receiving the pair split request from the host 100, the control processor 101 starts the pair split processing. The pair split request has two parameters. The volume number of the original volume and the volume number of the copy volume.

  In step 500, first, pair information 110 having the original volume number as the primary volume number 201 and the copy volume number as the secondary volume number 202 is selected, and the pair status 203 of the pair information 110 is set to “partitioning Is set. Next, the pair split copy process 107 is started and ended.

FIG. 6 shows a processing flow of the extent update processing 104. When a pair split request is issued and this is completed, data written to the original volume thereafter is not reflected on the copy volume. Therefore, the data stored in the copy volume becomes older and older, and is different from the latest data stored in the original volume. The host 100 issues an extent update request to the control device 112 when it is desired to match the data of the copy volume with the original volume for a specific area such as a data set or a file. The extent update request has four parameters. These are the volume number of the original volume, the volume number of the copy volume, the start address of an area such as a data set or a file to be matched between the original volume and the copy volume, and the de-end address. There may be a plurality of sets of the start address and the end address. Upon receiving the extent update request, the control processor 101 starts an extent update process 104. In step 600, first, pair information 110 having the volume number of the original volume received as a parameter in the primary volume number 201 and the volume number of the copy volume in the secondary volume number 202 is selected. Next, the extent information 205 in which the use flag 206 of the selected pair information 110 is 0 is selected. Next, the use flag 206 of the selected extent information 205 is set to 1, the start address 207 is set to the start address of an area such as a data set or a file received as a parameter, and the end address 208 is set to the end address received as a parameter. Set. In step 601,
The extent update copy processing 108 is started and ended.

  FIG. 7 shows a processing flow of the write processing 105. Upon receiving a write request from the host 100, the control processor 101 starts a write process 105. The write request has three parameters. The write data, the volume number of the volume that stores the write data, and the address in the volume that stores the write data.

  In step 700, the pair information 110 having the primary volume number 201 with the volume number received as a parameter is selected from the pair information 110 whose use flag 200 is 1. If there is no pair information 110 that satisfies the above condition, the process proceeds to step 707. If there is pair information 110 meeting the above conditions, the process proceeds to step 701.

  In step 701, regarding the pair information 110 selected in step 700, from the extent information 205 in which the use flag 205 is 1, the extent information in which the address received as a parameter is between the start address 207 and the end address 208 The presence or absence of 205 is checked. If there is no extent information 205 that satisfies the above condition, the process proceeds to step 708. If there is the extent information 205 that satisfies the above condition, the process proceeds to step 702.

  In step 702, it is checked whether the bit corresponding to the track corresponding to the address received as a parameter is 0 or 1 by referring to the in-division difference information 301 of the difference information 204 of the pair information 110 selected in step 700. In the case of 1, the process proceeds to step 703. If it is 0, the process proceeds to step 706.

  In step 703, data stored in the track corresponding to the address received as a parameter is read from the storage device 113 into the cache memory 111.

  In step 704, a copy of the data read in step 704 is created in the cache memory 111. The created copy is the data of the copy volume indicated by the secondary volume number 202 of the pair information 110 selected in step 700, but may be written to the storage device 113 at any time.

  In step 705, 0 is set to the bit checked in step 702.

In step 706, the difference bit of the difference information 204 of the pair information 110 selected in step 700 is set to 1. When the pair status 203 is “forming” or “completion completed”, 1 is set to a bit corresponding to the track corresponding to the address received as a parameter of the creating difference information 300 as a parameter. When the pair status 203 is “partitioning”, “1” is set to the bit corresponding to the track corresponding to the address received as a parameter in the dividing difference information 301 as a parameter. If the pair status 203 is “division completed” and it is determined in step 701 that the extent information 205 is present, “1” is set to the bit corresponding to the track corresponding to the address received as a parameter of the updating difference information 302 as a parameter. If the pair status 203 is “division completed” and it is determined in step 701 that there is no extent information 205, 1 is set to a bit corresponding to the track corresponding to the address received as a parameter of the in-division difference information 301 as a parameter.

  In step 707, the write data received as a parameter is stored in the cache memory 111, and the process ends.

  In step 708, the pair status 203 is checked. In the case of “partitioning”, the process proceeds to step 709. If it is not “dividing”, the process proceeds to step 706.

In step 709, it is checked whether the bit corresponding to the track corresponding to the address received as a parameter is 1 or 0 with reference to the in-creation difference information 300 of the difference information 204 of the pair information 110 selected in step 700. If 1, step 7
Go to 10. If it is 0, the process proceeds to step 706.

  In step 710, data stored in the track corresponding to the address received as a parameter is read from the storage device 113 to the cache memory 111.

In step 711, a copy of the data read in step 710 is created in the cache memory 111. The created copy is the data of the copy volume indicated by the secondary volume number 202 of the pair information 110 selected in step 700, but may be written to the storage device 113 at any time.

  In step 712, 0 is set to the bit checked in step 709, and the flow advances to step 706.

  FIG. 8 shows a processing flow of the pair creation copy processing 106. The pair creation copy process 106 is started from the pair creation process 102. The volume number of the original volume and the volume number of the copy volume are given as parameters.

  In step 800, the track number of the first track of the original volume is set in a variable i.

  In step 801, first, pair information 110 having the original volume number given as a parameter as the primary volume number 201 and the copy volume given as a parameter as the secondary volume number 202 is selected. Next, by referring to the in-creation difference information 300 of the difference information 204 of the selected pair information 110, it is checked whether the bit corresponding to the track whose track number is the variable i is 0 or 1. If it is 0, the process proceeds to step 805. In the case of 1, the process proceeds to step 802.

  In step 802, the data of the track whose track number is variable i is read from the storage device 113 into the cache memory 111.

  In step 803, a copy of the data taken in step 802 is created in the cache memory 111. The created data is the data of the volume having the volume number of the copy volume given as a parameter, but may be written to the storage device 113 at any time.

  At step 804, 0 is set to the bit referred to at step 801.

In step 805, it is checked whether the track on which the copy has been made is the end track of the volume. If the track is at the end, step 807
Proceed to. If the track is not the end track, the process proceeds to step 806.

  In step 806, 1 is added to the variable i, and the flow advances to step 801 to proceed to the next track.

  In step 807, “formation completed” is set in the pair status 203, and the process ends.

  FIG. 9 shows a processing flow of the pair split copy processing 107. The pair split copy process 107 is started from the pair split process 103. The volume number of the original volume and the volume number of the copy volume are given as parameters.

  In step 900, the track number of the first track of the original volume is set in the variable i.

  In step 901, first, pair information 110 having the original volume number given as a parameter as the primary volume number 201 and the copy volume given as a parameter as the secondary volume number 202 is selected. Next, by referring to the in-creation difference information 300 of the difference information 204 of the selected pair information 110, it is checked whether the bit corresponding to the track whose track number is the variable i is 0 or 1. If it is 0, the process proceeds to step 905. In the case of 1, the process proceeds to step 902.

  In step 902, the data of the track whose track number is variable i is read from the storage device 113 into the cache memory 111.

  In step 903, a copy of the data captured in step 902 is created in the cache memory 111. The created data is the data of the volume having the volume number of the copy volume given as a parameter, but may be written to the storage device 113 at any time.

  In step 904, 0 is set to the bit referred to in step 901.

  In step 905, it is checked whether the track on which the copy has been made is the end track of the volume. If it is the last track, the process proceeds to step 907. If the track is not the end track, the process proceeds to step 906.

  In step 906, 1 is added to the variable i, and the flow advances to step 901 to proceed to the next track.

  In step 907, “division completion” is set in the pair status 203, and the process ends.

  FIG. 10 shows a processing flow of the extent update copy processing 108. The extent update copy process 108 is started from the extent update process 103. As parameters, a volume number of the original volume, a volume number of the copy volume, a start address of an area such as a data set and a file, and an end address are given.

  In step 1000, the track number of the track corresponding to the start address given as a parameter is set in a variable i.

  In step 1001, first, pair information 110 having the original volume number given as a parameter as the primary volume number 201 and the volume number of the copy volume given as a parameter as the secondary volume number 202 is selected. Next, with reference to the in-division difference information 300 of the difference information 204 of the selected pair information 110, it is checked whether the bit corresponding to the track whose track number is the variable i is 0 or 1. If it is 0, the process proceeds to step 1005. In the case of 1, the process proceeds to step 1002.

  In step 1002, the data of the track whose track number is variable i is read from the storage device 113 into the cache memory 111.

  In step 1003, a copy of the data taken in step 1002 is created in the cache memory 111. The created data is the data of the volume having the volume number of the copy volume given as a parameter, but may be written to the storage device 113 at any time.

  In step 1004, 0 is set to the bit referred to in step 1001.

  In step 1005, it is checked whether the track on which the copy was made is a track corresponding to the end address given as a parameter. If it is the corresponding track, the process proceeds to step 1007. If it is not the corresponding track, the process proceeds to step 1006.

  In step 1006, 1 is added to the variable i, and the flow advances to step 1001 to proceed to the next track.

  In step 1007, first, the bits in the range of the start address and the end address given as parameters of the difference information 302 during update are read, and the read values are written in the difference information 301 during division. Next, the use flag 206 of the extent information 205 is set to 0, the extent information 205 is invalidated, and the process ends.

  FIG. 11 is a system configuration diagram showing the second embodiment of the present invention. The system includes a host 1100, a control device 1112, and a storage device 1113.

  The host 1100 issues various requests to the control device 112 according to a user's instruction or a user program. The storage device 1113 stores data. The control device 1112 reads data from or writes data to the storage device 1113 according to a request from the host 1100.

  The control device 1112 includes a control processor 1101, a control memory 1109, and a cache memory 1111.

  The control processor 1101 controls the control device 1112. In the control processor 1101, a pair creation process 1102, a pair split process 1103, a write process 1105, a pair creation copy process 1106, and a pair split copy process 1107 operate.

  The control memory 1109 stores control information necessary for the control processor 1101 to control the control device 1112, for example, pair information 1110. The cache memory 1111 temporarily stores data received from the host 1100 and data read from the storage device 1113.

FIG. 12 shows the data structure of the pair information 1110. The pair information 1110 includes a use flag 1200, a primary volume number 1201, a secondary volume number 1202, a pair status 1203, difference information 1204, a start address 1205, and an end address 1206. The use flag 1200 is a flag indicating whether the pair information 1110 is used, that is, whether the information in the pair information 1110 is valid. 1 indicates valid, and 0 indicates invalid. The primary volume number 1201 indicates the number of the original volume when a copy of the volume is created in response to a request from the host 1100. The secondary volume number 1202 is the number of the volume that stores a copy of the data of the original volume when a copy of the volume is created in response to a request from the host 1100. The pair status 1203 indicates how far the process of creating a copy of the volume has progressed, and has four values of “being formed”, “being formed”, “being split”, and “split completed”. The difference information 1204 is information indicating that data is different between the volume indicated by the primary volume number 1201 and the volume indicated by the secondary volume number 1202. The start address 1205 is an address indicating the start of an area such as a data set or a file, and the end address 1206 is an address indicating the end of a data set or a file.

  FIG. 13 shows the structure of the difference information 1204. The difference information 1204 is composed of a plurality of bits. One bit corresponds to one track. When the value is 0, the data of the corresponding track is indicated by a volume indicated by the primary volume number 1201 and a secondary volume number 1202. Indicates that they match, and when the value is 1, it indicates that they do not match. Of course, one bit may be applied to another unit.

FIG. 14 shows a processing flow of the pair creation processing 1102. The host 1100 issues a pair creation request when the control device 112 creates a copy of an area such as a certain data set or file. Upon receiving the pair creation request from the host 1100, the control processor 1101 starts the pair creation processing 1102. The pair creation request has four parameters. The volume number of a volume that contains an area such as a dataset or file to be copied (this is called a copy source volume), the volume number of a volume that stores copy data (this is called a copy destination volume), and the copy number An address indicating the start of an area such as a data set or a file for which the user wants to make a copy, and an address indicating the end of an area such as a data set or a file for which a copy is to be created. When a data set, a file, or the like is composed of a plurality of areas in a volume, the host 1100 passes a plurality of sets of start and end addresses to the control device 112 as parameters.

  In step 1400, the unused pair information 1110 whose use flag 1200 is 0 is selected, the use flag 1200 is set to 1, and the volume number of the copy source volume received from the host 1100 is set to the primary volume number 1201. Then, the volume number of the copy destination volume received from the host 1100 is set to the secondary volume number 1202, “being formed” is set to the pair status 1203, 1 is set to all bits of the difference information 1204, and the start address 1205 is set. An address indicating the start of an area such as a data set or a file received from the host 1100 is set in the field, and an address indicating the end of an area such as a data set or a file received from the host 1100 is set in the end address 1206. When a plurality of sets of the start address and the end address are given as parameters, this step is repeated, and the parameters are stored in the control memory 1109. In step 1401, a pair creation copy process 1106 is started, and the process ends.

FIG. 15 shows a processing flow of the pair division processing 1103. The host 1100 issues a pair split request to the control device 1112 when determining an area such as a data set or a file in the copy destination volume. Upon receiving the pair split request from the host 1100, the control processor 1101 starts the pair split processing 1103. The pair split request has four parameters. The volume number of the copy source volume, the volume number of the copy destination volume, the address indicating the start of the area of the data set or file to be determined, and the address indicating the end of the area of the data set or file to be determined. .

  In step 1500, first, pair information 1110 having the volume number of the copy source volume in the primary volume number 1201 and the volume number of the copy destination volume in the secondary volume number 1202 is selected, and the pair status 1203 of the pair information 1110 is set to " Set to "Dividing". Next, the pair split copy processing 1107 is started, and the processing ends.

  FIG. 16 shows a processing flow of the write processing 1105. Upon receiving a write request from the host 1100, the control processor 1101 starts a write process 1105. The write request has three parameters. The write data, the volume number of the volume that stores the write data, and the address in the volume that stores the write data.

  In step 1600, of the pair information 1110 in which the use flag 1200 is 1, the volume number received as a parameter has the primary volume number 1201 and the address received as a parameter is the start address 1205 and the end address 1206. Is selected as pair information 1110 between the two. If there is no pair information 1110 that satisfies the condition, the process proceeds to step 1607. If there is pair information 1110 that meets the above conditions, the process proceeds to step 1601.

  In step 1601, the pair status 1203 of the pair information 1110 selected in step 1600 is referred to. If the pair status 1203 is “being split”, the process proceeds to step 1602. If the pair status 1203 is not “split”, the process proceeds to step 1608.

  In step 1602, the difference information 1204 of the pair information 1110 selected in step 1600 is referred to. It is checked whether the bit corresponding to the track corresponding to the address received as a parameter is one. In the case of 1, the process proceeds to step 1603. If it is 0, the process proceeds to step 1607.

  In step 1603, the data of the track corresponding to the address received as a parameter is read from the storage device 1113 into the cache memory 1111.

  In step 1604, a copy of the data read in step 1603 is created in the cache memory 1111. The created data is data of the volume indicated by the secondary volume number 1202, but may be written to the storage device 1113 at any time.

  In step 1605, 0 is set to the bit checked in step 1602.

  In step 1607, the write data received as a parameter is stored in the cache memory 1111 and the process ends.

  In step 1608, the pair status 1203 of the pair information 1110 selected in step 1600 is referred to. If the pair status 1203 is “forming” or “completion completed”, the process proceeds to step 1606. If the pair status 1203 is neither “being formed” nor “completed”, the process proceeds to step 1607.

  In step 1606, 1 is set to the bit of the difference information 1204 corresponding to the track corresponding to the address received as a parameter.

  FIG. 17 shows a processing flow of the pair creation copy processing 1106. The pair creation copy process 1106 is started from the pair creation process 1102. As parameters, the volume number of the copy source volume, the volume number of the copy destination volume, an address indicating the start of an area such as a data set or a file, and an address indicating the end of an area such as a data set or a file are given.

In step 1700, first, the volume number of the copy source volume given as a parameter from the in-use pair information 1110 whose use flag 1200 is 1 is set as the primary volume number 1201, and the copy destination volume given as a parameter is used. Is selected as the sub-volume number 1202, the start address 1205 has the start address given as a parameter, and the end information 1206 has the end address 1206 given as a parameter. Next, the track number of the track corresponding to the start address 1205 of the selected pair information 1110 is set to the variable i.

In step 1701, it is checked whether the bit corresponding to the track whose track number is variable i is 0 or 1 by referring to the difference information 1204 of the pair information 1110 selected in step 1700. If it is 0, the process proceeds to step 1705. In the case of 1, the process proceeds to step 1702.

  In step 1702, the data of the track whose track number is variable i is read from the storage device 1113 into the cache memory 1111.

  In step 1703, a copy of the data taken in step 1702 is created in the cache memory 1111. The created data is the volume data of the volume number of the copy destination volume given as a parameter, but the data may be written to the storage device 1113 at any time.

  In step 1704, 0 is set to the bit referred to in step 1701.

In step 1705, it is checked whether or not the copied track has reached the track corresponding to the end address 1206. If it has reached step 170
Proceed to 7. If not, the process proceeds to step 1706.

  In step 1706, 1 is added to the variable i, and the flow advances to step 1701 to proceed to the next track.

  In step 1707, “formation completed” is set in the pair status 1203, and the process ends.

  FIG. 18 shows a processing flow of the pair split copy processing 1107. The pair split copy process 1107 is started from the pair split process 1103. As parameters, the volume number of the copy source volume, the volume number of the copy destination volume, an address indicating the start of an area such as a data set or a file, and an address indicating the end of an area such as a data set or a file are given.

In step 1800, the volume number of the copy source volume given as a parameter is set to the primary volume number 1201 from the used pair information 1110 whose use flag 1200 is 1, and the copy destination volume given as a parameter is used. Is selected as the sub-volume number 1202, the start address 1205 has the start address given as a parameter, and the end information 1206 has the end address 1206 given as a parameter. Next, the track number of the track corresponding to the start address 1205 of the selected pair information 1110 is set to the variable i.

  In step 1801, it is checked whether the bit corresponding to the track whose track number is variable i is 0 or 1 by referring to the difference information 1204 of the pair information 1110 selected in step 1800. If it is 0, the process proceeds to step 1805. In the case of 1, the process proceeds to step 1802.

  In step 1802, the data of the track whose track number is variable i is read from the storage device 1113 into the cache memory 1111.

  In step 1803, a copy of the data captured in step 1702 is created in the cache memory 1111. The created data is the volume data of the volume number of the copy destination volume given as a parameter, but the data may be written to the storage device 1113 at any time.

  In step 1804, 0 is set to the bit referred to in step 1801.

  In step 1805, it is checked whether the copied track has reached the track corresponding to the end address 1206. If it has reached, the process proceeds to step 1807. If not, the process proceeds to step 1806.

  In step 1806, 1 is added to the variable i, and the flow advances to step 1801 to proceed to the next track.

  In step 1807, “division completion” is set in the pair status 1203, and the process ends.

  FIG. 19 is a system configuration diagram showing the third embodiment of the present invention. The system includes a host 1900, a control device 1901, and a storage device 1912. The host 1900 issues various requests to the control device 1901 according to a user's instruction or a user program. The storage device 1912 stores data. The control device 1901 reads data from or writes data to the storage device 1912 according to a request from the host 1900.

  The control device 1901 includes a control processor 1902, a control memory 1910, and a cache memory 1911.

  The control processor 1902 controls the control device 1901. In the control processor 1902, pair creation processing 1903, extent division processing 1904, extent combination processing 1905, write processing 1906, extent division copy processing 1907, extent combination copy processing 1908, and pair formation copy processing 1913 operate. The control memory 1910 stores control information required for the control processor 1902 to control the control device 1901, for example, pair information 1909. The cache memory 1911 temporarily stores data received from the host 1900 and data read from the storage device 1912.

FIG. 20 shows the data structure of the pair information 1909. The pair information 1909 includes a use flag 2001, a primary volume number 2002, a secondary volume number 2003, difference information 2004, a pair status 2005, and extent information 2006. The use flag 2001 is a flag indicating whether the pair information 1909 is used, that is, whether the information in the pair information 1909 is valid. 1 indicates valid, and 0 indicates invalid. The primary volume number 2002 indicates the number of the original volume when a copy of the volume is created in response to a request from the host 1900. The secondary volume number 2003 indicates the number of a volume that stores a copy of the data of the original volume when a copy of the volume is created in response to a request from the host 100. The difference information 2004 is information indicating that data differs between the volume indicated by the primary volume number 2002 and the volume indicated by the secondary volume number 2003. The pair status 2005 indicates how far the process of making a copy of the entire volume or a part of the volume has progressed, and is “being formed” and “completed”.
, “Extent split”, “extent split completed”, and “extent merged”. The extent information 2006 is information indicating where a region such as a data set or a file is stored in the volume, and is composed of a start address 2007 and an end address 2008. The start address 2007 is an address indicating the start of an area such as a data set or a file. The end address 2008 is an address indicating the end of an area such as a data set or a file.

  FIG. 21 shows the structure of the difference information 2004. The difference information 2004 is composed of two types of bitmaps, that is, the creating difference information 2100 and the dividing difference information 2101. One bit corresponds to one track, and when the value is 0, it indicates that the data of the corresponding track matches the volume indicated by the primary volume number 2002 and the volume indicated by the secondary volume number 2003, When the value is 1, it indicates that they do not match. Of course, one bit may be applied to another unit.

  FIG. 22 shows a processing flow of the pair creation processing 1903. The host 1900 issues a pair creation request when the control device 1901 creates a copy of a certain volume. Upon receiving the pair creation request issued by the host 1900, the control processor 1902 starts the pair creation processing 1903. The pair creation request has two parameters. A volume number of a volume for creating a copy (this volume is called an original volume) and a volume number of a volume for storing copy data (this volume is called a copy volume).

  In step 2200, unused pair information 1909 whose use flag 2001 is 0 is selected, 1 is set in the use flag 2001, and the volume number of the original volume received from the host 1900 is set in the primary volume number 2002. , Sets the volume number of the copy volume received from the host 1900 to the secondary volume number 2003, sets “forming” to the pair status 2005, and sets 1 to all the bits of the creating difference information 2100 of the difference information 2004. , 0 is set to all bits of the dividing difference information 2101.

  In step 2201, the pair creation copy process 1913 is started and ended.

FIG. 23 shows a processing flow of the extent division processing 1904. The host 1900 issues an extent division request when determining data to be stored in the copy volume for a specific area in the volume. Upon receiving the extent division request issued by the host 1900, the control processor 1902 starts the extent division processing. The extent division request includes a volume number of one original volume, a volume number of one copy volume, a start address indicating a start end of an area where one or more data is to be determined, and an end indicating one or more end ends. It has a parameter consisting of an address.

  In step 2300, first, pair information 1909 having the primary volume number 2002 as the volume number of the original volume received as a parameter, and the secondary volume number 2003 as the volume number of the received copy volume as a parameter is selected. Next, “extent in progress” is set in the pair status 2005 of the selected pair information 1909. Next, the received start address is set as a parameter to the start address 2007 of the extent information 2006 of the selected pair information 1909, and the received end address is set to the end address 2008 as a parameter.

  In step 2301, extent division copy processing is started and ended.

FIG. 24 shows a processing flow of the extent combining processing 1905. Upon receiving the extent combining request issued by the host 1900, the control processor 1900 starts extent combining processing 1905. The extent combination request has a parameter composed of the volume number of the original volume and the volume number of the copy volume.

  In step 2400, first, pair information 1909 having the original volume number given as a parameter as the primary volume number 2002 and the copy volume given as a parameter as the secondary volume number 2003 is selected and selected. In the pair status 1905 of the pair information 1909, “extent merge” is set. Next, the extent combination copy processing 1908 is started and ended.

  FIG. 25 shows a processing flow of the pair creation copy processing 1913. The pair creation copy process 1913 is started from the pair creation process 1903. The volume number of the original volume and the volume number of the copy volume are given as parameters.

  In step 2500, the track number of the first track of the original volume given as a parameter is set in the variable i.

  In step 2501, first, pair information 1909 having the volume number of the original volume given as a parameter as the primary volume number 2002 and the volume number of the copy volume given as a parameter as the secondary volume number 2003 is selected. Next, with reference to the in-creation difference information 2100 of the difference information 2004 of the selected pair information 2000, it is checked whether the bit corresponding to the track whose track number is the variable i is 0 or 1. If it is 0, the process proceeds to step 2505. In the case of 1, the process proceeds to step 2502.

  In step 2502, the data of the track whose track number is variable i is read from the storage device 1912 to the cache memory 1911.

  In step 2503, a copy of the data read in step 2502 is created in the cache memory 1911. The created data is the data of the volume having the volume number of the copy volume given as a parameter, but may be written to the storage device 1912 at any time.

  In step 2504, 0 is set to the bit referred to in step 2501.

  In step 2505, it is checked whether the track whose track number is variable i is the end of the volume corresponding to the volume number of the original volume given as a parameter. In the case of the last track, the process proceeds to step 2507. If the track is not the end track, the process proceeds to step 2506.

  In step 2506, the variable i is updated, and the flow advances to step 2501 to proceed to the next track.

  In step 2507, “formation completed” is set in the pair status 2005 of the pair information 1909 selected in step 2501, and the process ends.

  FIG. 26 shows a processing flow of the write processing 1906. Upon receiving a write request from the host 1900, the control processor 1902 starts write processing 1906. The write request has three parameters. The write data, the volume number of the volume that stores the write data, and the address in the volume that stores the write data.

  In step 2600, the pair information 1909 having the primary volume number 2002 with the volume number received as a parameter is selected from among the pair information 1909 whose use flag 2001 is 1. If there is no pair information 1909 that satisfies the above condition, the process proceeds to step 2608. If there is pair information 1909 that meets the above conditions, the process proceeds to step 2601.

  In step 2601, the pair status 2005 of the pair information 1909 selected in step 2600 is checked. If the pair status 2005 is “extent split”, the process proceeds to step 2602. Otherwise, the process proceeds to step 2607.

  In step 2602, it is determined whether the address in the volume received as a parameter is included between the start address 2007 and the end address 2008 of the extent information 2006 by referring to the extent information 2006 of the pair information 1909 selected in step 2600. If it is included, the process proceeds to step 2603. If not included, the process proceeds to step 2607.

  In step 2603, reference is made to the in-creation difference information 2100 of the difference information 2004 of the pair information 1909 selected in step 2600 to check whether the bit corresponding to the track corresponding to the address in the volume given as a parameter is 0 or 1. . If it is 0, the process proceeds to step 2607. In the case of 1, the process proceeds to step 2604.

  In step 2604, the data of the track corresponding to the address in the volume received as a parameter is read from the storage device 1912 to the cache memory 1911.

  In step 2605, a copy of the data read in step 2604 is created in the cache memory 1911. The created copy is the data of the volume indicated by the secondary volume number 2003 of the pair information 1909 selected in step 2600, but may be written to the storage device 1912 at any time.

  In step 2606, 0 is set to the bit checked in step 2603.

  In step 2607, first, the pair status 2005 of the pair information 1909 selected in step 2600 is checked. When the pair status 2005 is “being formed”, “being formed”, or “being combined extents”, it corresponds to the track corresponding to the address in the volume given as a parameter of the difference information 2100 during the creation of the difference information 2004 Set the bit to 1. If the pair status 2005 is “extent split” or “extent split complete”, 1 is set to the bit corresponding to the track corresponding to the address in the volume given as the parameter of the split difference information 2100 of the difference information 2004. Set.

  In step 2608, the write data received as a parameter is stored in the cache memory 1911, and the process ends.

  FIG. 27 shows a processing flow of the extent division copy processing 1907. The extent division copy processing 1907 is started from the extent division processing 1904, and the volume number of the original volume and the volume number of the copy volume are given as parameters.

  In step 2700, first, pair information 1909 having the volume number of the original volume given as a parameter as the primary volume number 2002 and the volume number of the copy volume given as a parameter as the secondary volume number 2003 is selected. Next, one piece of extent information 2006 of the selected pair information 1909 is selected, and a start address 2007 is set to a variable i.

  In step 2701, the bit corresponding to the track whose track number is variable i is checked with reference to the creating difference information 2100 of the difference information 2004 of the pair information 1909 selected in step 2700. If it is 0, the process proceeds to step 2705. In the case of 1, the process proceeds to step 2702.

  In step 2702, the data of the track whose track number is the variable i is read from the storage device 1912 to the cache memory 1911.

  In step 2703, a copy of the data read in step 2702 is created in the cache memory 1911. The created data is data of a volume corresponding to the volume number of the copy volume given as a parameter, but may be written to the storage device 1912 at any time.

  In step 2704, 0 is set to the bit checked in step 2701.

  In step 2705, it is checked whether the track whose track number is variable i is a track corresponding to the end address 2008. In the case of the corresponding track, the process proceeds to step 2708. Otherwise, go to step 2706.

  In step 2706, the variable i is updated, and the flow advances to step 2701 to proceed to the next track.

  In step 2708, it is checked whether or not the processing from step 2700 to step 2706 has been performed on all the extent information 2006 of the pair information 1909 selected in step 2700. If the processing has been completed, the process proceeds to step 2707. If there is unprocessed extent information 2006, the process proceeds to step 2700, and the process is executed for the range described in the next extent information 2006.

  In step 2707, “extent division completed” is set in the pair status 2005 of the pair information 1909 selected in step 2700, and the process ends. As a result, data of a specific range of the original volume given as a parameter of the extent division request and at the time when the extent division request was issued is created in the copy volume.

  FIG. 28 shows a processing flow of the extent combination copy processing 1908. The extent combination copy processing 1908 is started from the extent combination processing 1905, and the volume number of the original volume and the volume number of the copy volume are given as parameters.

  In step 2800, first, pair information 1909 having the volume number of the original volume given as a parameter as the primary volume number 2002 and the volume number of the copy volume given as a parameter in the secondary volume number 2003 is selected. Next, one piece of extent information 2006 of the selected pair information 1909 is selected, and a start address 2007 is set to a variable i.

  In step 2801, the bit corresponding to the track whose track number is variable i is checked by referring to the in-division difference information 2101 of the difference information 2004 of the pair information 1909 selected in step 2800. If it is 0, the process proceeds to step 2805. In the case of 1, the process proceeds to step 2802.

  In step 2802, the data of the track whose track number is the variable i is read from the storage device 1912 to the cache memory 1911.

  In step 2803, a copy of the data read in step 2802 is created in the cache memory 1911. The created data is a volume corresponding to the volume number of the copy volume given as a parameter, but may be written to the storage device 1912 at any time.

  In step 2804, 0 is set to the bit checked in step 2801.

In step 2805, it is checked whether the track whose track number is variable i is a track corresponding to the end address 2008. In the case of the corresponding track, the process proceeds to step 2808. Otherwise, go to step 2806.

  In step 2806, the variable i is updated, and the flow advances to step 2801 to proceed to the next track.

  In step 2808, it is checked whether or not the processing from step 2800 to step 2806 has been performed on all the extent information 2006 of the pair information 1909 selected in step 2800. If the processing has been completed, the process proceeds to step 2807. If there is unprocessed extent information 2006, the process advances to step 2800 to execute processing for the range described in the next extent information 2006.

  In step 2807, “formation completed” is set in the pair status 2005 of the pair information 1909 selected in step 2800, and the process ends.

In order to improve the performance of a disk device, there is a disk array and a technology for writing write data to a plurality of disks in parallel. The volumes described in the first embodiment, the second embodiment, and the third embodiment may be configured by applying the disk array technology. The volumes described in the first embodiment, the second embodiment, and the third embodiment may be areas stored in a single disk without applying the disk array technology. . The original volumes described in the first embodiment, the second embodiment, and the third embodiment are configured by applying the disk array technology, and the copy volumes are not applied by the disk array technology. , May be an area stored on a single disk. The original volume described in the first embodiment, the second embodiment, and the third embodiment is an area stored on a single disk without applying the disk array technology, and The volume may be configured by applying the disk array technology.

1 shows a configuration of a system according to a first embodiment of the present invention. The contents of the control information required by the control processor when implementing the present invention will be described. 4 shows a configuration of difference information of the control information. 10 shows a processing flow when a pair creation request is received from a host. 10 shows a processing flow when a pair split request is received from a host. 10 shows a processing flow when an extent update request is received from a host. 4 shows a processing flow when a write request is received from a host. 4 shows a processing flow of pair creation copy processing. 4 shows a processing flow of pair split copy processing. 5 shows a processing flow of extent update copy processing. 7 shows a configuration of a system according to a second embodiment of the present invention. The contents of the control information required by the control processor when implementing the present invention will be described. 4 shows a configuration of difference information of the control information. 10 shows a processing flow when a pair creation request is received from a host. 10 shows a processing flow when a pair split request is received from a host. 4 shows a processing flow when a write request is received from a host. 4 shows a processing flow of pair creation copy processing. 4 shows a processing flow of pair split copy processing. 9 shows a configuration of a system according to a third embodiment of the present invention. The contents of the control information required by the control processor when implementing the present invention will be described. 4 shows a configuration of difference information of the control information. 10 shows a processing flow when a pair creation request is received from a host. 10 shows a processing flow when an extent division request is received from a host. 14 shows a processing flow when an extent combination request is received from a host. 4 shows a processing flow of pair creation copy processing. 10 shows a processing flow when a write request is received from a host. 4 shows a processing flow of extent division copy processing. 4 shows a processing flow of extent combination copy processing.

Explanation of reference numerals

100 host 101 control processor 109 control memory 111 cache memory 112 control device 113 storage device.

Claims (3)

In a storage device system having a function of creating a copy (copy volume) of data stored in a volume (original volume) at a certain time in accordance with an instruction from a host, a range included in the original volume from the host is indicated. Means for receiving a start address and an end address, and reading the data in the range specified by the received start address and end address from the original volume and writing the data to the copy volume, thereby obtaining the start address of the copy volume. And a means for matching data in the range specified by the end address with data of the original volume again.   2. The storage device system according to claim 1, wherein the storage unit stores a location of a difference between the original volume and the copy volume generated by a write process of the host, and the start address and the end address of the copy volume. A computer system for reading only the location of the stored difference from the original volume and writing the data to the copy volume when matching the data of the range again with the data of the original volume. A host, a storage device system connected to the host, a unit for receiving a start address and an end address indicating a specific range belonging to a volume from the host, and a unit for creating a copy of data included in the specific range. A computer system comprising:

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