JPH11237955A - External storage subsystem and record creation method - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To reduce the connection time between a higher-level device and an external storage subsystem in a record creation process required when constructing a database. After receiving a WRKD command, an external storage subsystem disconnects a connection with a higher-level device based on a pseudo completion report and creates a plurality of records in the external storage subsystem. The connection time 52 between the external storage subsystems is reduced, and the throughput between the host device and the external storage subsystem is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a record creation method for an external storage subsystem, and more particularly to a record creation method for creating many records at once.

[0002]

2. Description of the Related Art At the stage of constructing a database,
The host device needs to create many records in the external storage subsystem. Hereinafter, a conventional data creation method will be described with reference to Table 1 and FIG. Table 1
FIG. 2 is a diagram showing a command used for record creation and its parameters (excerpt), and FIG. 2 shows a correspondence between a command received from a higher-level device and an operation of the command in the storage control device in a conventional data creation process. Note that FIG.
Does not indicate the time synchronization between the command received and the operation corresponding to the command.

[0003]

[Table 1]

[0004] When a record is created in a storage device having a track format of the CKD system (count key data system), a higher-level device uses a Define Extent command (21: hereinafter referred to as DX command) and a Locate Record command (22: hereinafter LR). Command), the position on the storage device is determined, and then the number of Write Couns for the number of domain counts of the LR command (see the parameters in Table 1)
t Key and Data (32, 33, 34, 35: WR
CKD command).

[0005] The external storage subsystem creates a record in the data storage device 13 by executing a record creation operation 41 based on the WRCKD command 32. Similarly, a record creation operation 42 is performed for the WRKDD command 33 and a record creation operation 43 is performed for the WRKDD command 34 to create a target number of records. Last WRCKD command 35
After the record creation operation 44 is performed, the completion report 61 is issued and the record creation processing is terminated, but the connection between the higher-level device and the external storage subsystem is maintained for a time corresponding to 51. .

[0006]

In the conventional external storage subsystem, when a plurality of records having the same data part length and the same content and the record numbers are created in ascending order, the upper level device has the same number of WRCKDs as the number of records to be created. You need to issue a command.

An object of the present invention is to reduce the connection time between a host device and an external storage subsystem during a record creation process, that is, to issue a single WRCKD command to reduce the length and contents of a data portion. The object is to provide an external storage subsystem that creates a plurality of equal records.

[0008]

According to the present invention, the host device specifies a command issued when a record is created in the external storage subsystem or its parameter to indicate that the function according to the present invention is to be used, and the external storage subsystem Give instructions to Thereafter, the host device issues only one WRCKD command to the external storage subsystem. The external storage subsystem creates the number of records specified in advance by the parameters of the command based on the contents of the record received by the WRCKD command.

According to the present invention, the command issued when the host device creates a record indicates that the function of the present invention is to be used and the number of records to be created, and the external storage subsystem issues only one. By creating a record by repeatedly using the WRKD command to be executed, a data creation method for reducing the communication load between the host device and the external storage subsystem at the time of creating the record is realized.

[0010]

FIG. 1 is a configuration diagram of a computer system according to an embodiment of the present invention. Reference numeral 10 denotes a host device that issues commands, and reference numeral 11 denotes an external storage subsystem. The external storage subsystem 11 has a storage control device 12 and storage devices 15 to 17. The storage control device for controlling the storage device includes a cache memory 13 for temporarily storing data transferred between the host device and the storage device, and a data buffer 14 for storing commands from the host device. As the storage device, a magnetic disk device that supports the track format of the CKD system can be used. The present invention can be used even if the external storage subsystem is a disk array subsystem as long as it emulates the CKD method.

FIG. 3 is a diagram showing a correspondence between a command received from a higher-level device and an operation in the storage controller for the command in the data creation process using the present invention, and FIG. 4 is a record creation process according to the present invention. It is a flowchart of FIG. FIG. 3 is similar to FIG. 2 in that FIG. 3 does not show the time synchronization of the received command and the operation corresponding to the command.

First, the host device 10 transmits the DX command 2
2. Following the LR command 24, the WRKD command 3
6 is issued (101, 102). The upper level device 10
An instruction to use the record creation method of the present invention, positioning information, and the number of created records are indicated by the parameters of the R command 24. Indicating the number of records to be created uses a domain count, which conventionally indicates the number of commands that follow. The value of the domain count is set in variable D. The positioning information, the number of records to be created, the length of the records, and the like can be arbitrarily set within a range permitted by the external storage subsystem that intends to create data. The storage control device that has received these commands performs the positioning process at the record content storage address in the cache memory (10
3).

[0013] The storage controller subsequently receives the WRCKD command 36 (104). And the storage control unit is WR
Of the data received by the CKD command 36, the data in the count section is
4 (105), and the record contents are stored in the cache memory 13 (106). If the LR command 24 does not instruct to use the record creation method of the present invention, the storage controller creates a record by a conventional method. (117). When the instruction to use the record creation method of the present invention is given, the storage control device disconnects the connection with the higher-level device by the pseudo completion report 62 (108). Therefore, the connection between the host device and the external storage subsystem is maintained only for a time corresponding to 52, which is almost equal to the processing time of a single record.

Thereafter, when all records have been created, the processing is terminated (109, 118). If there is an uncreated record, the number of created records is counted (110).

Thereafter, when the cylinder switch and the track switch do not occur in the next record (111, 11)
2), the external storage subsystem starts the next record creation processing 46. The storage controller is a data buffer 1
1 is added to the record number of the counting section stored in No. 4 (113), and the process of positioning the record created in the cache memory 13 to the next record by the WRKD command 36 is performed (114).

In the record creation process in the storage controller, if the record to be created does not fit in the cylinder (111), a cylinder switch process is performed in the positioning process. The storage control device adds 1 to the cylinder address of the count section stored in the data buffer 14, sets the head address to 0 and the record number to 1 (119), and performs positioning processing to the next record (1).
14). Similarly, when a cylinder switch occurs (112), the storage control device adds 1 to the head address of the count section stored in the data buffer 14, sets the record number to 1 (119), and positions the next record. Processing is performed (114).

Then, after transferring the count section in the data buffer 14 to the positioned record position in step 114 (115), padding data equal to the record length designated by the count section is created in the cache memory 13 (117). The padding data must have the same length as the record contents received by the WRKD command 36.
It is desirable that the record created in step 3 be copied.

Thereafter, returning to step 107, the data creation processing is repeated until the number of records indicated by the domain count is created. That is, the data creation processing 47
Then, the record number of the counting unit stored in the buffering device 12 is further incremented by 1, and the counting unit in the buffering device 12 is transferred to the next record position of the record created in the data storage device 13 by the data creation processing 46. After that, the padding data equal to the length of the record included in the counting section is created in the data storage device 13.

After the number of records specified by the command 24 has been created in the cache memory 13 in this manner,
By notifying the completion report 62 to the host device, the host device recognizes that the requested record (45, 46, 47,..., 48) has been created in the external storage subsystem. Then, the record created on the cache memory is stored in the storage device.

In the record creation process in the storage controller, if the record to be created does not fit in the cylinder, a cylinder switch process is performed in the positioning process. The storage control device adds 1 to the cylinder address of the counting unit stored in the data buffer 14, sets the head address to 0 and the record number to 1 (118),
Continue creating records. Similarly, when the cylinder switch occurs, the storage control device operates the data buffer 14.
Is added to the head address of the counting section stored in
The record number is set to 1 (119), and the creation of the record is continued.

In the course of these operations, records on the same external storage subsystem that are on tracks that have not been updated in the present record creation processing are maintained in the state before the present record creation processing. As a result, the host device can create a record having a required number and length at an arbitrary position without destroying other data in the same external storage subsystem.

Further, the data creation method according to the embodiment of the present invention is conventionally supported as long as it can transmit three information, ie, an instruction to use the record creation method of the present invention, positioning information, and the number of created records. Various application forms are possible, such as a method of adding new contents to the parameters of the command being used or a method of employing an entirely new command. Table 2 shows an example of the embodiment of the present invention. Although Example 1 in Table 2 corresponds to the above-described example, records can be created based on the flowchart in FIG. 4 in other examples. In Examples 1 and 2,
Conventionally, the number of created records (WRCK following LR command)
Since the domain counter of the LR command that stores the number of D commands is used as a parameter indicating the number of records to be created, it is possible to minimize the change of the program on the host device side.

[0023]

[Table 2]

[0024]

According to the present invention, the external storage subsystem receives an instruction on the number of records to be created from the higher-level device,
A record can be created based on a WRCKD command issued from a higher-level device. That is, since the external storage subsystem according to the present invention can create records of a number equal to or more than the number of WRCKD commands issued from the higher-level device to generate records, the communication between the higher-level device and the external storage subsystem can be performed. The load can be reduced, and the connection time between the host device and the external storage subsystem can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an example of a configuration of a computer system that implements the present invention.

FIG. 2 is a diagram illustrating a correspondence between a command received from a higher-level device and an operation in the storage controller with respect to the command in a conventional data creation process.

FIG. 3 is a diagram showing a correspondence between a command received from a higher-level device and an operation corresponding to the command in a storage control device in a data creation process according to the present invention.

FIG. 4 is a diagram showing a flowchart of a data creation process according to the present invention.

[Explanation of symbols]

10: Host device 11: External storage subsystem 12: Storage controller 13: Cache memory 14: Data buffer 15, 16, 17: Magnetic disk drive 21, 22: DX (Define Extent) command 23, 24: LR (Locate Record) ) Command 32, 33, 34, 35, 36: WRCKD command (Write Count Key and Data) 41, 42, 43, 44, 45, 46, 47, 48: Record creation operation in the storage controller

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroshi Nishijima 2880 Kozu, Odawara-shi, Kanagawa Storage Systems Division, Hitachi, Ltd.

Claims (14)

[Claims] 1. An external storage subsystem having a storage device and a storage control device that receives a command from a higher-level device and controls the storage device, wherein the storage control device receives a command from a higher-level device during a record creation process. An external storage subsystem for creating more records than the number of received data creation commands. 2. The external storage subsystem according to claim 1, wherein said record creation command is a WRCKD command for creating a CKD format record. 3. The external storage subsystem according to claim 1, wherein said storage control device has a cache memory, and creates a record on said cache memory. 4. An external storage subsystem having a storage device and a storage control device that receives a command from a higher-level device and controls the storage device, wherein the storage control device receives a command from a higher-level device during a record creation process. An external storage subsystem, which receives an instruction on the number of records to be created and creates more records than the number of received record creation commands. 5. The external storage subsystem according to claim 4, wherein said record creation command is a WRCKD command for creating a CKD format record. 6. The external storage subsystem according to claim 4, wherein said storage control device has a cache memory, and creates a record in said cache memory. 7. An external storage subsystem having a storage device and a storage control device that receives a command from a higher-level device and controls the storage device, wherein the storage control device receives a command from a higher-level device during a record creation process. An external storage subsystem, which receives a command including an instruction for the number of records to be created and one record creation command, and creates the number of records designated by a higher-level device based on the record creation command. 8. The external storage subsystem according to claim 7, wherein said record creation command is a WRCKD command for creating a CKD format record. 9. The external storage subsystem according to claim 7, wherein said storage control device has a cache memory, and creates a record in said cache memory. 10. A record creation method for an external storage subsystem having a storage device and a storage control device that receives a command from a host device and controls the storage device, wherein the storage control device creates a record from the host device. Receiving a command including an instruction for the number of records to be recorded and one record creation command, storing the record creation command, creating one record based on the record creation command,
A record creation method, comprising issuing a pseudo completion report to a host device and repeating record creation until the number of records specified by the host device is created. 11. The record creation command is a WRCKD command for creating a CKD format record, and when the record creation is repeated, the record number of the counting section is set to 1
11. The record creation method according to claim 10, wherein the number is increased by one. 12. The record creation method according to claim 10, wherein said storage control device has a cache memory, and creates a record in said cache memory. 13. When a track switch occurs during repeated record creation, the head address is set to 1
12. The record creation method according to claim 11, wherein the addition is performed, the record number is set to 1, and the record creation is continued. 14. If a cylinder switch occurs during repeated record creation, the cylinder address is incremented by 1, the head address is set to 0, the record number is set to 1, and record creation is continued. Item 11
The record creation method described.